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psikeyhackr
11-11-2007, 01:05 AM
And now for a video that is completely different.

http://www.youtube.com/watch?v=z0kUICwO93Q

No one else seems to be demanding to know the tons of steel and tons of concrete on every floor.

The NIST tells us the building oscillated for 4 minutes. How do you compute how much kinetic energy shook the entire building versus how much did structural damage at the point of impact? Isn't that necessary to do an accurate computer model?

psik

PhilosophyGenius
11-11-2007, 10:24 PM
I think a better model would have been showing a few floors on the top of that model getting knocked off or squshed down and seeing how fast the whole thing collapses- if at all.

psikeyhackr
11-12-2007, 01:54 PM
The model is intended to demonstrate that the behavior of the structure changes with the distribution of mass. The questions point out that we have not been told the distribution of mass in steel and concrete in 6 years.

The trouble with building an accurate collapse model is the strength to weight ratio of matter increases as things get smaller. An ant is stronger than you in relation to its size. An accurate collapse model could not be built without the information which I am saying we are not being told.

psik

dMole
11-12-2007, 02:49 PM
No one else seems to be demanding to know the tons of steel and tons of concrete on every floor.

The NIST tells us the building oscillated for 4 minutes. How do you compute how much kinetic energy shook the entire building versus how much did structural damage at the point of impact? Isn't that necessary to do an accurate computer model?
psik

I kept getting interrupted when I tried to watch the video, but the physics appeared sound to me.

http://hyperphysics.phy-astr.gsu.edu/hbase/newt.html#ntcon

I remember Newton's own words saying that an applied force is proportional to the rate of change of momentum of the body (not F=ma per se). F=dp/dt, if you will. It's really a matter of semantics for classical mechanics though. In quantum mechanics and optics, photon momenta and radiation "pressure" gets a little "trickier" since you can't weigh the things...

There are a few places that mention the steel and concrete floor masses/loads.

[metric units from my review]
http://911research.wtc7.net/mirrors/guardian2/wtc/godfrey.htm

http://www.911research.com/papers/trumpman/CoreAnalysisFinal.htm

http://911research.wtc7.ent/mirrors/guardian2/wtc/eng-news-record.htm

http://www.journalof911studies.com/volume/200704/SzambotiSustainabilityofControlledDemolitionHypoth esisForDestructionofTwinTowers.pdf

http://911research.wtc7.net/wtc/evidence/blueprints.html

[I've found some questionable findings in this MIT paper IMHO]
http://web.mit.edu/civenv/wtc/PDFfiles/Chapter%20VI%20Materials%20&%20Structures.pdf

[Very suspect findings in this paper with gems like:]
"Additionally, the FEMA team carried the computer analysis only to a point in time immediately after the impacts; they did not consider the effects of the fire."
http://132.236.67.210/EngrWords/issues/ew01/StevensonC_PR1.pdf

Regarding the WTC Tower oscillations, these should be impulse-driven, damped oscillations (likely harmonic due to the symmetry in Tower construction). Impulse physics is not well understood AFAIK (usually instrumented crash-test-dummy type stuff). And yes, these SHOULD BE accounted for in an ACCURATE computer model... Who has the source code of the simulations exactly?

dMole
11-12-2007, 04:19 PM
How do you compute how much kinetic energy shook the entire building versus how much did structural damage at the point of impact?
psik

Hi again Psi,

I made an inquiry about the engine rotational energy over at Pilots 4 Truth (P4T). Unfortunately, I've been unable to find any data on the jet engines' Moment of Inertia (I), needed for a rotational energy calculation.

http://z9.invisionfree.com/Pilots_For_Truth/index.php?showtopic=9397&view=findpost&p=10063991

Linear KE is easy (= 1/2 m * v^2), if you can find an accurate number/concensus on the combined plane/passenger/fuel mass (good luck- I haven't so far). Oh yeah, UA175 that struck the South Tower WTC2 appears to have been traveling MUCH faster than a Boeing 767's maximum cruise velocity [which SHOULD BE faster than low altitude V_max], too.

http://z9.invisionfree.com/Pilots_For_Truth/index.php?showtopic=9179&view=findpost&p=10011348

Hmmmm...

d

psikeyhackr
11-20-2007, 04:19 PM
Some people at Purdue made this simulation:

http://www.youtube.com/watch?v=cddIgb1nGJ8

I sent them this email about it:

Greetings,

Congratulations on a great looking simulation.

Since some of the kinetic energy caused the entire building to shake and some did damage at the impact zone I was wondering how it was determined how much did what?

In six years I have not heard how much steel and concrete were on each level of the buildings so I am wondering how that information can be obtained.

You see I made my own video but the simulation is based on a physical model. I am having trouble understanding how this incident can be analyzed without the distribution of steel and concrete being taken into account. How many tons of steel were on the impact floors of the south tower to weaken in 56 minutes? I haven't heard that in 6 years.

http://www.youtube.com/watch?v=z0kUICwO93Q

Sincerely,

-----------------------------------------

I got this respone from Chris Hoffmann:

Thanks for your interest.
Please contact Professor Sozen regarding the building particulars.
Best wishes, Chris Hoffmann

______________________
Christoph M. Hoffmann, Computer Science
Director, Rosen Center for Advanced Computing
Purdue University, West Lafayette, IN 47907
ph: 765-494-6185, fax: 765-494-0739
www.cs.purdue.edu/homes/cmh
______________________

I emailed Professor Sozen the same day but I have gotten no response so far.

psikey

dMole
11-22-2007, 07:36 PM
I got this respone from Chris Hoffmann:

Thanks for your interest.
Please contact Professor Sozen regarding the building particulars.
Best wishes, Chris Hoffmann

______________________
Christoph M. Hoffmann, Computer Science
Director, Rosen Center for Advanced Computing
Purdue University, West Lafayette, IN 47907
ph: 765-494-6185, fax: 765-494-0739
www.cs.purdue.edu/homes/cmh (http://www.cs.purdue.edu/homes/cmh)
______________________

I emailed Professor Sozen the same day but I have gotten no response so far.

psikey

Don't you know that we were supposed to accept the MSM and Kean Commission versions of physical laws? Hell, just to humor we "CT'ists", they did [government appointed and funded] FEMA/ASCE and NIST studies, not to mention all that wonderful PM (Pseudo-Mechanics) and pHistory Channel "debunking."

It looks to me like Mr. Hoffmann was QUITE quick to wash his hands of your inquiry. I'd stay on Professor Sozen until he responds (but it took me 3 years to get here, and I've been studying the WTC "attacks" for 3 years more, and I don't plan on going away any time soon- that is what the OCT and PTB would prefer, you know).

psikeyhackr
12-08-2007, 09:35 PM
This certainly puts an interesting spin on the IMPACT if true.

http://www.youtube.com//watch?v=x2upl977dsY

But lots of people involved with large commercial planes should have known this years ago. Aeronautical engineering students should have known it. If it is true what does it say about our engineering schools?

This is a site with info on aerodynamics:

http://www.phy6.org/stargaze/Sflight2.htm

It says the air density at sea level is 4 times that at 30,000 feet therefore the drag on the airliner would be 4 times as great. The engines would need 4 times as much power to overcome that drag. It seems unlikely that a normal airliner would have engines that over powered.

These are videos of large aircraft at low altitudes:

Low Pass (http://www.youtube.com/watch?v=DMQBC0U6Mcw)

Hot Dog (http://www.youtube.com/watch?v=Wzidphcp6N8)

So if the planes in the videos were doing 300 mph and drag is proportional to the square of velocity.

300 * 300 = 90,000 500 * 500 = 250,000

250,000/90,000 = 2.8

Going from 300 mph to 500 mph at the same altitude means 2.8 times as much drag. But going from 700 feet to 30,000 feet means 1/4th as much drag.

2.8 * 0.25 = 0.7

So doing 500 mph at 30,000 feet is less drag on the planes than 300 mph at 700 feet. So if the engines were only using 50% of their maximum thrust when cruising at 30,000 feet they could not produce enough thrust to do 500 mph at 700 feet. I think there is a very good chance that ex-Boeing engineer is correct. Since MIT says the plane that hit the south tower was doing 503 mph this makes 9/11 look very weird.

And the weirdness just doesn't stop.

Switched Planes (http://www.amics21.com/911/flight175/second.html)

psikey

N320AW
12-09-2007, 08:24 PM
[QUOTE= Oh yeah, UA175 that struck the South Tower WTC2 appears to have been traveling MUCH faster than a Boeing 767's maximum cruise velocity [which SHOULD BE faster than low altitude V_max], too.

/QUOTE (http://quote/)]

Could you be a little more clear on what the above means? I lost ya on that!

N320AW

dMole
12-10-2007, 01:21 AM
Hi N320AW (is this a tail number or ??),

Ummm, where to start- the link was to a 23-PAGE thread over at P4T. I used some reasonably accurate approximation methods based upon latitude/longitude and the ~12 second radar "sweep" time interval to estimate the "average" velocity between radar data returns.

Aside from the 888 knots (1022 mph) velocity anomaly at 08:55:47 EDT for UA175 at 28400 feet Mode C altitude (derived DIRECTLY from the USAF 84 RADES .XLS data file), I found an average (arithmetic mean) velocity for the UA175 flight of 391 kts (453 mph). Incidentally, the "high" velocities started well before the alleged hijack time:

"The 9/11 Commission concludes that Flight 175 is then hijacked within the next four minutes (see (Between 8:42 a.m. and 8:46 a.m.) September 11, 2001 (http://www.cooperativeresearch.org/timeline.jsp?day_of_9/11=ua175&timeline=complete_911_timeline#a842hijackerstakeov er)). [9/11 Commission, 7/24/2004, pp. 7 (http://web.archive.org/web/20041020144854/http://www.decloah.com/mirrors/9-11/911_Report.txt)]"

http://www.cooperativeresearch.org/timeline.jsp?day_of_9/11=ua175&timeline=complete_911_timeline

Disregarding the one radar "anomaly", I found a 2nd highest velocity of 546 kts (628 mph) at 08:53:47 EDT. The V_mo/M_mo for a Boeing 767 is listed at 360 knots / 0.86 mach.
http://rgl.faa.gov/Regulatory_and_Guidance_Library%5CrgMakeModel.nsf/0/A8694BE7B7AC6C178625731E006944BC?OpenDocument

Another problem is that the USAF 84 RADES cover letter submitted to the FBI 13 September 2001 lists flight UA175 as a Boeing 757, not a B767. Incidentally, the same cover letter lists UA93 (Pennsylvania) as a Boeing 747...

FWIW, the V_mo/M_mo for a B757 is only slightly lower at 350 kts / 0.86 mach.
http://www.757.org.uk/limits/lim1.html

http://rgl.faa.gov/Regulatory_and_Guidance_Library%5CrgMakeModel.nsf/0/A5A31D7DF6F5CEC28625718B0065C20B?OpenDocument

According to Joseph Keith, the ex-Boeing engineer in the above video, the turbofan engines are capable of 330 mph at 700 feet AGL, but the airframe is only capable of 220 mph before it "begins to shake itself apart" according to the video.

FEMA, Kean/Hamilton, NIST, and others all put the impact velocity with WTC2 South above 500 mph from what I recall. Several of the 2+2's here are coming up 9 it would seem...

N320AW
12-10-2007, 04:08 PM
Thanks.


What altitude was this aircraft at when it's GS was 546 knots?


About J. Keiths comments: Why does he use such numbers of 220 & 330 MPH? I don't understand his analogy concerning the engines are " capable of 330 MPH." Capable of what?

dMole
12-10-2007, 05:09 PM
I found the 545.64 kts at 32000 feet Mode C/ 33600 feet primary radar height. My calculations give a 0.86 mach velocity of 502.61 kts for this 32 Kft altitude.

At P4T there is a thread about Flight Test Limits being verified to 0.92 mach by Boeing engineers (not certain on plane model). My calculations give 537.68 kts (again 32 Kft) at this 0.92 mach "overtest" level that mentions flapping wings and nearly-destructive flight. In the conspicuous absence of FDR's and CVR's, we can only speculate about the goings on inside the Boeing, but if I were hypothetically tasked with "suicidal Jihadist Boeing missile duty," I'd probably want to be certain that the plane ACTUALLY made it to the target rather than risk destroying the Boeing in mid-flight.

I believe that Joseph Keith was referring to the low-altitude increased air density and drag, especially on the jet turbofan engines (only rated to 105% of maximum rated shaft RPM from my research in FAA datasheets). A female Boeing aerospace engineer in one of the videos was laughing via telephone about the feasibility of 500 mph velocity near 800 feet ASL. Incidentally, the last 3 RADES radar returns averaged 501 mph by my estimates, so there is ONE thing that approximately checks with the "official" box-cutter conspiracy story (although it appears to contradict the 2 Boeing engineers).

Another interesting anomaly that I believe contradicts the "eyewitness" and video accounts of the UA175/WTC2 South impact- the RADES data shows an altitude decrease of over 8000 feet in the last minute of flight. Wasn't the video of a relatively "flat" Boeing approach, banking to the port side immediately before impact? I haven't calculated the dive angle yet from dive & lat/lon (GS velocity), but the USAF/FBI RADES data seems to contradict the video "evidence" IMHO- both simply CANNOT be true from my observations.

N320AW
12-10-2007, 08:40 PM
dMole: Any Boeing engineer, worth his diploma, wouldn't make such silly claims about these " speeds." The numbers are of course, way too low, that it is laughable.

Jet aircraft, after departure climb at 250 KIAS (287 SLMPH) until reaching 10,000 feet. This is done because the maximum indicated airspeed below that altitude is 250 kts. Obviously, during climb, the TAS increases.

On this descent of 8,000 ft./min. Almost nothing can descend at that rate. The worst way to try to get an airplane down as fast as possible is to lower the nose and reduce the power. You'll get a good rate of descent alright, but not 8,000 FT./Min. Emergency descents in jet aircraft are performed by slowing the plane to Vge, lowering the landing gear, and establishing a certain speed given by that AC's flight manual. This procedure will get you down faster than any other method.

I can readily believe that the second aircraft struck the North tower around 500 MPH. To do so, it would take the application of full-power and a slight dive, but it could be done. That aircraft will not attain a speed of 500 MPH in level flight at that low altitude.

Something else of interest about aircraft in general. Sometime in the 1980's, a disgruntled/fired employee of PSA airlines in CA entered the cockpit of a BAE-146 and shot both pilots. He then pushed the control wheel down and entered a vertical dive until the aircraft impacted the ground near Paso Robles, CA. Witnesses stated they heard two explosions prior to impact. The first, was the sonic boom created by this not very aerodynamic 4 engine jet . . .the second explosion was the aircraft's vertical impact. NTSB determined there was no aircraft parts far away from the wreckage. This indicates the aircraft did not breakup while exceeding the speed of sound. A B767 could very easily exceed the speed of sound in a powered steep descent. Of course, I don't feel any of this reflects on 9-11-01.

Also, the quick turn to the left just before the aircraft hit the North tower, I an sure, was NOT this pilot getting " more bang for the buck " in attempting to create a more vertical impact zone! It is my opinion this pilot(?) experienced what sky-divers call " ground rush." Ever see skydivers floating in the air as it appears? Not so when a free-falling object gets within about 1000 ft. of the ground and moving about 125 MPH. That ground suddenly comes up at an alarming rate. I feel this is what happened to this B767's pilot. 2-3 miles away from the WTC, no matter what the speed, the closure appears minimal. Just aim your nose at something until you hit it, right? Wrong! What appears to be a straight course to an object at miles is not particularly true. Those last few thousand feet will show the error of your ways and as the " rush " effect becomes clear . . . the pilot will have to do some quick last second course corrections to hit what is being aimed at.

dMole
12-10-2007, 10:47 PM
dMole: Any Boeing engineer, worth his diploma, wouldn't make such silly claims about these " speeds." The numbers are of course, way too low, that it is laughable.

That would be an issue to support with documentation or test data or else to take up with either Joe Keith or the female Boeing engineer in the telephone call. I have never claimed to have nor have ever worked for Boeing or been a certified pilot. I have however worked in aerospace/defense engineering, and I contend that Boeing and others do not have the "markets cornered" on mathematics, physics, aerodynamics, hydrodynamics, metallurgy, materials science, error analysis, or forensic research/investigation. Furthermore, USAF 84 RADES/FBI compiled the .XLS radar data (released in Oct. 2007, after a third party's FOIA request) that I independently audited (from the .ISO file that I downloaded).


Something else of interest about aircraft in general. Sometime in the 1980's, a disgruntled/fired employee of PSA airlines in CA entered the cockpit of a BAE-146 and shot both pilots. He then pushed the control wheel down and entered a vertical dive until the aircraft impacted the ground near Paso Robles, CA. Witnesses stated they heard two explosions prior to impact. The first, was the sonic boom created by this not very aerodynamic 4 engine jet . . .the second explosion was the aircraft's vertical impact. NTSB determined there was no aircraft parts far away from the wreckage. This indicates the aircraft did not breakup while exceeding the speed of sound. A B767 could very easily exceed the speed of sound in a powered steep descent. Of course, I don't feel any of this reflects on 9-11-01.

I agree with you that the BAe-146-200 of PSA Flight #1771 and a Boeing 767/757 (ambiguity per Kean-Hamilton Committee/FEMA/NIST/USAF/FBI) is something of an apples-to-cherries comparison. According to the FAA datasheet for a BAe-146, its "speeds" are listed as:

M_mo = 0.70 (standard, 0.73 optional)
V_mo (to 8000 feet) = 250 KIAS
V_mo (8000 - 22 950 feet) = 300 KIAS
V_mo (T.O.) = 160 KIAS

http://rgl.faa.gov/Regulatory_and_Guidance_Library%5CrgMakeModel.nsf/0/14846A9C50743A18862572B3005354A8?OpenDocument

The NTSB Incident Docket says:
http://ntsb.gov/ntsb/brief.asp?ev_id=20001213X32679&key=1

"
NTSB Identification: DCA88MA008 .
The docket is stored on NTSB microfiche number 34799.
Scheduled 14 CFR Part 121: Air Carrier PACIFIC SOUTHWEST AIRLINES
Accident occurred Monday, December 07, 1987 in SAN LUIS OBISPO, CA
Probable Cause Approval Date: 1/4/1989
Aircraft: BRITISH AEROSPACE BAE-146-200, registration: N350PS
Injuries: 43 Fatal.A RECENTLY DISCHARGED USAIR EMPLOYEE BOARDED PSA FLT 1771 AFTER HAVING LEFT A GOODBYE MESSAGE WITH FRIENDS. HE BYPASSED SECURITY AND CARRIED ABD A BORROWED 44 CALIBER PISTOL. A NOTE WRITTEN BY THIS PSGR, FOUND IN THE WRECKAGE, THREATENED HIS FORMER SUPERVISOR AT USAIR, WHO WAS ABOARD THE FLT. AT 1613, THE PLT RPTD TO OAKLAND ARTCC THAT HE HAD AN EMERGENCY AND THAT GUNSHOTS HAD BEEN FIRED IN THE AIRPLANE. WITHIN 25 SECONDS, OAKLAND CTR CONTROLLERS OBSERVED THAT PSA 1771 HAD BEGUN A RAPID DESCENT FM WHICH IT DID NOT RECOVER. WITNESSES ON THE GND SAID THE AIRPLANE WAS INTACT AND THERE WAS NO EVIDENCE OF FIRE BEFORE THE AIRPLANE STRUCK THE GND IN A STEEP NOSE-DOWN ATTITUDE. THE CVR TAPE REVEALED THE SOUNDS OF A SCUFFLE AND SEVERAL SHOTS WHICH WERE APPARENTLY FIRED IN OR NEAR THE COCKPIT. THE PISTOL WAS FOUND IN THE WRECKAGE WITH 6 EXPENDED ROUNDS. FAA RULES PERMITTED AIRLINE EMPLOYEES TO BYPASS SECURITY CHECKPOINTS.


The National Transportation Safety Board determines the probable cause(s) of this accident as follows:

CONTROL INTERFERENCE..INTENTIONAL..PASSENGER
SABOTAGE..INTENTIONAL..PASSENGER
EMOTIONAL REACTION..PASSENGER

Contributing FactorsSECURITY..INADEQUATE..COMPANY/OPERATOR MANAGEMENT
PROCEDURE INADEQUATE..COMPANY/OPERATOR MANAGEMENT
INSUFF STANDARDS/REQUIREMENTS,OPERATION/OPERATOR..FAA(ORGANIZATION)"

I found no evidence of explosions, velocity estimates, or sonic booms at NTSB.

Much like 9/11/2001, futher investigation revealed conflicting information:

http://www.airdisaster.com/special/special-pa1771.shtml

"The sound of the gunshot is picked up on the cockpit voice recorder, and seconds later the sound of the cockpit door opening is heard. A female, presumed to be a Flight Attendant, advises the cockpit crew that “we have a problem.” The Captain replies with “what kind of problem?” Burke then appears at the cockpit door and announces “I'm the problem,” simultaneously firing two more shots that fatally injure both pilots.

Several seconds later, the CVR picks up increasing windscreen noise as the airplane pitches down and begins to accelerate. A final gunshot is heard as Burke fatally shoots himself. Airspeed continues to build until 13,000 feet, when traveling at a velocity of 1.2x Mach, the aircraft breaks apart and the Flight Recorders cease functioning.

All 44 passengers and crew aboard PSA Flight 1771 died as the aircraft crashed into a Farmer's field in the Santa Ana Hills."

Did the BAe 146 break up? Did it "crash" intact into the farmer's field? Do we trust the eyewitnesses or the "broken" flight data recorder (presumably last logged at 13,000 feet AGL)? Do we trust the engineers who have worked for Boeing? Would the UA175 Boeing 757/767 (especially the engines and control surfaces) survive and continue to operate MANEUVERABLY at 500 mph at 700-1000 feet ASL?

I suspect that one would have better luck gathering facts on PSA 1771 (which TRULY WAS hijacked with a .44 revolver IMHO), from the multiplying inconsistencies that I and others have already found in AA11, AA77, UA175, and UA93 data and "official" documents/reports.

psikeyhackr
12-10-2007, 10:51 PM
A B767 could very easily exceed the speed of sound in a powered steep descent.
Would the aircraft survive breaking the sound barrier?

The Concord SST was shaped somewhat differently than a 767.

psik

AuGmENTor
12-10-2007, 11:06 PM
Wow, this is really the rocket scientist thread these days. Keep talking gentlemen! I may not have any idea what the hell you're talking about, but I feel smarter just having read it!

N320AW
12-11-2007, 02:05 AM
Would the aircraft survive breaking the sound barrier?

The Concord SST was shaped somewhat differently than a 767.

psik

Sure, thats not a problem.

N320AW
12-11-2007, 02:19 AM
I found the 545.64 kts at 32000 feet Mode C/ 33600 feet primary radar height. My calculations give a 0.86 mach velocity of 502.61 kts for this 32 Kft altitude.

At P4T there is a thread about Flight Test Limits being verified to 0.92 mach by Boeing engineers (not certain on plane model). My calculations give 537.68 kts (again 32 Kft) at this 0.92 mach "overtest" level that mentions flapping wings and nearly-destructive flight. In the conspicuous absence of FDR's and CVR's, we can only speculate about the goings on inside the Boeing, but if I were hypothetically tasked with "suicidal Jihadist Boeing missile duty," I'd probably want to be certain that the plane ACTUALLY made it to the target rather than risk destroying the Boeing in mid-flight.

I believe that Joseph Keith was referring to the low-altitude increased air density and drag, especially on the jet turbofan engines (only rated to 105% of maximum rated shaft RPM from my research in FAA datasheets). A female Boeing aerospace engineer in one of the videos was laughing via telephone about the feasibility of 500 mph velocity near 800 feet ASL. Incidentally, the last 3 RADES radar returns averaged 501 mph by my estimates, so there is ONE thing that approximately checks with the "official" box-cutter conspiracy story (although it appears to contradict the 2 Boeing engineers).

Another interesting anomaly that I believe contradicts the "eyewitness" and video accounts of the UA175/WTC2 South impact- the RADES data shows an altitude decrease of over 8000 feet in the last minute of flight. Wasn't the video of a relatively "flat" Boeing approach, banking to the port side immediately before impact? I haven't calculated the dive angle yet from dive & lat/lon (GS velocity), but the USAF/FBI RADES data seems to contradict the video "evidence" IMHO- both simply CANNOT be true from my observations.

Just to illustrate the Boeing engineers data is flawed; as you know the Vmo of a B767 is 360 KCAS. Thats approx 414 MPH. That aircraft will certainly fly at low altitude on the " barber pole." Thats the redline airspeed. Well, if the aircraft is certified to operate at a a max IAS of 414 MPH (360 kts.) the engineers are very wrong. It is that simple.

Please advise, when you have the time, what you are trying to determine with your data. I would be very interested. Maybe I missed something along the way.

I can only speak as a pilot, not an engineer. Maybe we could put our heads together on some of this.

psikeyhackr
12-11-2007, 10:45 PM
Sure, thats not a problem.What is the basis for that claim?

dMole
12-11-2007, 11:17 PM
Just to illustrate the Boeing engineers data is flawed... That aircraft will certainly fly at low altitude on the " barber pole." Thats the redline airspeed. Well, if the aircraft is certified to operate at a a max IAS of 414 MPH (360 kts.) the engineers are very wrong. It is that simple.

I don't recall the video mentioning engineers' data. Apparently Joe Keith helped develop the "shaker system" that Boeing uses to qualification test their airframes, so I would consider this to be "expert opinion" in absence of documentation or EMPIRICAL flight or wind tunnel test data that conclusively refutes the 2 (corroborating) Boeing engineers' opinions. I'm more familiar with military and NASA policies and procedures, but I would expect that the Boeing test engineers had CONSIDERABLE input in writing the performance specifications and Flight Manuals based upon EMPIRICAL flight and wind tunnel test data and on FAA and CFR regulations.

See CFR Title 14:
PART 25—AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES

http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr;sid=13cf78c0a70960dda36526f6c9a860fc;rg n=div5;view=text;node=14%3A1.0.1.3.11;idno=14;cc=e cfr#14:1.0.1.3.11.3.162.2

PART 33—AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES

(Subparts E & F cover Turbine engines)

http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&sid=13cf78c0a70960dda36526f6c9a860fc&rgn=div5&view=text&node=14:1.0.1.3.16&idno=14

I have been unsuccessfully searching for a clear cut definition of "low altitude" for several weeks now, with respect to maximum airframe-safe velocities at various altitudes/air densities. Below 18,000 feet AGL, "Mach" is effectively a red herring IMHO, and I'm QUITE certain that WTC1, 2, & 7 were WELL below 3000 feet ASL. So far, Boeing, GE, Pratt Whitney, and Rolls-Royce aircraft/jet engine/aerospace engineers have been conspicuously silent on the feasibility of the Kean-Hamilton/FEMA/ASCE/NIST/Purdue/MIT/PM/History Channel/MSM "official" bin Ladin boxcutter conspiracy story.

Perhaps the following would explain the scarcity and silence of Boeing engineers:

http://seattlepi.nwsource.com/business/339881_boeingsurveillance16.html

I'm personally not certain that an identity-challenged B757/B767 (especially the turbofan engines and control surfaces) are capable of velocities WELL over V_mo and nearly-aerobatic maneuvers at "low altitude". There are over a dozen engine possibilities for these 2 Boeing models, by the way. Incidentally, V_mo, V_d, and V_fc were ALL allegedly exceeded by UA175 from 08:19:16 EDT at 10400 feet AGL with no Mode 3 return (allegedly STILL at the hands of a professional United Airlines pilot for roughly another 25 minutes) until at LEAST 09:01:59 EDT. People can certainly speculate on various Boeing airframe and engine capabilities and on pilot and/or hijacker behaviors in the conspicuous absence of AA11 and UA175 FDR's and CVR's, but I prefer to stick to documentable or experimentally-verified numbers.

For the B767 flavor, the FAA datasheets tell us:

Airspeed Limits:
VD = 420 KCAS to 17,854 ft/.91M above 23,000 ft, linear variation between these points.
VFC = 390 KCAS to 17,600 ft/382 KCAS at 23,000 ft/.87M above 26,000 ft, linear variation between these points.
VMO = 360 KCAS/.86M
VLE = 270 KCAS/.82M
VLO = 270 KCAS/.82M
For other airspeed limits, see the appropriate FAA-Approved Airplane Flight Manual.

http://rgl.faa.gov/Regulatory_and_Guidance_Library%5CrgMakeModel.nsf/0/A8694BE7B7AC6C178625731E006944BC?OpenDocument

If UA175 was really a B757 as USAF 84 RADES informed the FBI on 13 September 2001:

Airspeed Limits:
VMO = 350 KCAS/.86 M
VLE = 270 KCAS/.82 M
VLO = 270 KCAS/.82 M

For other airspeed limits, see the appropriate FAA-Approved Airplane Flight Manual listed in Note 2.

http://rgl.faa.gov/Regulatory_and_Guidance_Library%5CrgMakeModel.nsf/0/A5A31D7DF6F5CEC28625718B0065C20B?OpenDocument

For the non-pilots on the BBS (myself included, but I've known numerous pilots and aircraft engineers and mechanics),
KCAS = knots calibrated airspeed
KIAS= knots indicated airspeed
KTAS= knots true airspeed
V_mo= velocity, maximum operating
M_mo= mach (velocity), maximum operating
VD= Design diving speed (usually 1.4 times normal operating speed, representative of airframe "survivability" in overspeed conditions- not necessarily turbofan engine "safe")
VFC= "maximum speed for stability characteristics."

http://en.wikipedia.org/wiki/V1_speed#V1w

I haven't seen any conclusive numbers on wind speeds aloft, so that issue is likely a goose chase 6 years later.


Please advise, when you have the time, what you are trying to determine with your data. I would be very interested. Maybe I missed something along the way.

Wellll, the TRUTH for starters... Let me reiterate, this is the USAF 84 RADES .XLS data provided to/for the FBI that I independently audited, not "my" data. I and 3 other researchers/investigators have conclusively proven (to our satisfaction) that the OCT "boxcutter" fable conflicts both with itself and with the USAF 84 RADES .XLS data (which is also self-contradictory).

I and most of my professional tools deal with numbers, not JREF/Pseudo-Mechanics/pHistory Channel/MSM rhetorical sophistry and propaganda methods (but I'm growing increasingly versed on their "methods" however.) My preliminary work has been independently confirmed by 4 RADES radar stations and by 2 other researchers/investigators using different analytical methods. (Incidentally, my velocities corrected for 42 degrees North latitude appear to be the most "conservative" of the bunch). I haven't even brought up the "bumblebee altitudes" and "stealth" portions of the four 9/11 flights, either. Then there are the AA77 and UA93 data recorder anomalies... Do you know of any PUBLICLY available FAA radar data as of Dec 2001 to cross-check against the USAF RADES data? I don't...

As I stated early on, I have posted several DOZEN relevant posts on the 23 PAGE thread over at P4T that might save me considerable typing over here:

http://z9.invisionfree.com/Pilots_For_Truth/index.php?showtopic=9179&view=findpost&p=10011348

Note: the original post appears to have been something of a "dark pink" herring if we disregard the singular 888 kts/1021 mph velocity observed by the Riverhead, NY RADES station at 08:55:47 EDT (that I haven't seen an explanation for yet), and the thread originator seems to have disappeared.

Hmmmm...

N320AW
12-12-2007, 02:23 AM
Sure, thats not a problem.

Many aircraft that were not designed for flight above the sound barrier, have either intentionally or un-intentionally exceed the speed of sound. The German ME-262 for example.

When you said " survive " I took that to mean the structural integrity of the aircraft was at issue. The problem which most aircraft have in approaching and transitioning above the speed of sound (transonic) is one of possible un-controlability. Buffeting is frequently encountered, but the biggest problem is the AC's tendency to nose down, sometimes to the point of the pilot not being able to recover from the dive.

Some aircraft today have what is known as a mach trim system. This system will automatically introduce the proper amount of elevator trim to compensate for the aircraft's nose down characteristics when at high speed.

By the way, the B757 has the system . . . the B767 does not!

dMole
12-12-2007, 02:26 AM
Would the aircraft survive breaking the sound barrier?

The Concord SST was shaped somewhat differently than a 767.

psik

Hi psik,

The airfoil shape certianly comes into play in subsonic, transonic, and supersonic drag. I just located the following information on "wave drag" (Wikipedia is NOT one of my preferred sources, but this information looked legitimate to me). And AuGgie, I'm already sensing a 1980's transvestite joke coming here. ;)

From:
http://en.wikipedia.org/wiki/Supersonic_travel

"Below supersonic speeds the energy radiated to drag is roughly proportional to the square of airspeed and the density of the air. However, as speeds approach the speed of sound, the phenomenon of wave drag (http://en.wikipedia.org/wiki/Wave_drag) appears. This is a powerful form of drag that starts at about Mach 0.8 (http://en.wikipedia.org/wiki/Mach_number) and ends around Mach 1.2, (transonic (http://en.wikipedia.org/wiki/Transonic) speeds). Between these speeds the coefficient of drag (http://en.wikipedia.org/wiki/Coefficient_of_drag) (Cd) is approximately tripled. Above the transonic range Cd drops dramatically again, although it remains 30 to 50% higher than at subsonic speeds. This means that a supersonic aircraft has to have considerable extra power to overcome wave drag, although cruising performance above that speed is more efficient."

From:
http://en.wikipedia.org/wiki/Wave_drag

"Wave drag is caused by the formation of shock waves (http://en.wikipedia.org/wiki/Shock_wave) around the aircraft. Shock waves radiate away a considerable amount of energy, energy that is experienced by the aircraft as drag. Although shock waves are typically associated with supersonic flow, they can form at much lower speeds at areas on the aircraft where, according Bernoulli's principle (http://en.wikipedia.org/wiki/Bernoulli%27s_principle), local airflow accelerates to supersonic speeds over curved areas. The effect is typically seen at speeds of about Mach 0.8 (http://en.wikipedia.org/wiki/Mach_number), but it is possible to notice the problem at any speed over that of the critical Mach (http://en.wikipedia.org/wiki/Critical_Mach) of that aircraft's wing. The magnitude of the rise in drag is impressive, typically peaking at about four times the normal subsonic drag. It is so powerful that it was thought for some time that engines would not be able to provide enough power to easily overcome the effect, which led to the concept of a "sound barrier (http://en.wikipedia.org/wiki/Sound_barrier)".

See also:
http://www.centennialofflight.gov/essay/Theories_of_Flight/Transonic_Flow/TH19.htm

http://en.wikipedia.org/wiki/Aeroelasticity

The increased "wave drag" makes me wonder how much velocity above Mach 0.86 at various altitudes the applicable Boeing high bypass turbofan pairs are ACTUALLY capable of generating...

A retired Royal Navy aerospace engineer (with decades of experience with subsonic, transonic, and supersonic naval aircraft including the supersonic F4 Phantom fighter) provided me with the following excellent Concorde SST engine link:

http://www.concordesst.com/powerplant.html

NOTE: Rapid reheat or "reheat" is termed "afterburner" in US aerospace circles. Also note the variable ramps to restrict and slow incoming airflow in the 4 Concorde Rolls-Royce/SNECMA engine air intakes.

All of my research so far points to the jet engines being the upper velocity limiting factor for high-bypass subsonic/low transonic Boeing turbofans built by either GE, Pratt Whitney, or Rolls-Royce (in the 757 case). Considerable engineering work has obviously gone into the supersonic Concorde engines to overcome transonic and supersonic challenges, and the Boeing engines are missing nearly ALL of these design adaptations. My research is confirmed by the retired Royal Navy engineer at:

http://z9.invisionfree.com/Pilots_For_Truth/index.php?showtopic=9179&view=findpost&p=10265987

Research is being done on supercritical airfoils and supercritical turbofan blades, but I didn't find many sources on these two that didn't require a subscription service.

d

dMole
12-12-2007, 02:40 AM
Do you know of any PUBLICLY available FAA radar data as of Dec 2001 to cross-check against the USAF RADES data? I don't...


Correction past "edit thirty": make that PUBLICLY available FAA radar data as of Dec 2007.

dMole
12-12-2007, 04:14 PM
These are videos of large aircraft at low altitudes:

Low Pass (http://www.youtube.com/watch?v=DMQBC0U6Mcw)

Hot Dog (http://www.youtube.com/watch?v=Wzidphcp6N8)

So if the planes in the videos were doing 300 mph and drag is proportional to the square of velocity.

300 * 300 = 90,000 500 * 500 = 250,000

250,000/90,000 = 2.8

Going from 300 mph to 500 mph at the same altitude means 2.8 times as much drag. But going from 700 feet to 30,000 feet means 1/4th as much drag.

2.8 * 0.25 = 0.7

So doing 500 mph at 30,000 feet is less drag on the planes than 300 mph at 700 feet. So if the engines were only using 50% of their maximum thrust when cruising at 30,000 feet they could not produce enough thrust to do 500 mph at 700 feet. I think there is a very good chance that ex-Boeing engineer is correct. Since MIT says the plane that hit the south tower was doing 503 mph this makes 9/11 look very weird.
...
psikey

Also see this New Zealand 757 video:

http://www.youtube.com/watch?v=50BRFzVxDH8&NR=1

All 3 planes looked "flapped" to the stops IMHO, and the 757 had landing gear extended in one pass (increased drag), but they looked MUCH closer to stall or landing speeds than 500mph (or even 300mph) to me. I grew up near the Bonneville Salt Flats speedway, so I've seen several 400+ mph ~4100 feet ASL "low altitude" "cars" and nearly 300mph top-fuel "1/4 mile" dragsters live, but perhaps I can't estimate velocity...:burnout:

I'd bet that all 3 planes were EXTREMELY "light" (i.e. NO passengers and small flight crew) for lower-liability "stunt" flying. I doubt the fuel load was much either for logistics and risk reasons (but fuel "slosh" is a common problem in aerospace engineering). Less weight = less lift needed, no?

I'm fairly certain that the Boeing 727 has a much smaller moment of inertia (and MUCH higher roll rates) than a 757/767 due to the 727's three engines being MUCH closer to the fuselage centerline than the 2 massive wing-mounted engines for a B757/B767 (or B777 and B787 for that matter).

B727 shows a "Zero fuel weight" of 100,000 lb / 45,360 kg

http://en.wikipedia.org/wiki/Boeing_727#Specifications

B757 shows an "Operating empty" weight of roughly 128,000 lb / 58,000 kg

http://www.airliners.net/info/stats.main?id=101

B767-200 shows "Empty weight" of 176,650 lb / 80,130 kg

B767-200ER shows "Empty weight" of 181,610 lb / 82,380 kg

http://en.wikipedia.org/wiki/Boeing_767#Specifications

B707-120B shows "Operating empty weight" of 122,533 lb / 55,589 kg

B707-320B lists "Operating empty weight" of 146,400 lb / 66,406 kg

http://www.airliners.net/info/stats.main?id=87

Based on my physics, I'd say your older B727 and B707 are the "sporty" Boeing models, with the B757 getting an honorable mention. Of course, we would need to add a reasonable amount for fuel load and a minimal flight crew to each of the above numbers, based upon my 2 assumptions about "stunt" flying above.

As an aside that indicates Boeing could likely answer our "low altitude" speed questions, NASA says of the B767-200:

"Although of conventional configuration, the detailed aerodynamic design of the 767-200 is highly refined, as might be expected by the nearly 25 000 hours of wind-tunnel time required in the development of the aircraft. To place this wind-tunnel effort in perspective, 14 000 and 4000 wind-tunnel hours were expended in developing the Boeing 747 and 727, respectively."

http://www.hq.nasa.gov/pao/History/SP-468/ch13-6.htm

psikeyhackr
12-12-2007, 04:20 PM
Hi psik,

The airfoil shape certianly comes into play in subsonic, transonic, and supersonic drag. I just located the following information on "wave drag" (Wikipedia is NOT one of my preferred sources, but this information looked legitimate to me). And AuGgie, I'm already sensing a 1980's transvestite joke coming here. ;)

dThanks dMole.

What about the aircraft as a whole?

I am not a pilot or knowledgable about aerodynamics but my "gut" reaction is that a 767 would be destroyed trying to make the transition to supersonic. I have doubts about it being able to handle 500 mph at 1000 feet but I am not sure.

psik

dMole
12-12-2007, 04:35 PM
Yes Psik, you are correct. Most people consider the wings (and horizontal tail sections) as the "airfoil" per se.

Two decades of studying military aircraft, missiles, and rockets makes me think of flattened things like F-15, F-22, B-2, F-117, SR-71, etc. as a "cumulative" airfoil. I also have an off-n-on, 20+ year, "loose" history with the USAF, so my perception of "aircraft capabilities" is admittedly not from a commercial airliner perspective- those scare me a little. No comment from me on "spacecraft," however. ;)

If you replace my generic use of "airfoil" with "entire Boeing airframe [to include 2 high-bypass turbofan engines]", you'll probably like my statement a little better.

EDIT: add the F-14 Tomcat (with its movable wings) to the above list- one HELL of an interceptor design there, but my sources tell me Tommy's soon bound for pasture...

dMole
12-17-2007, 10:05 AM
Hi psik,

My searching found the following Univ. of Akron article, but you'd need a subscription service to get a copy. I usually check local university and city libraries, and engineering, electronics, physics, and chemistry departments for tech. articles to copy before purchasing.

http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JENMDT000131000010001066000001&idtype=cvips&gifs=yes

My BS detector already went off from the abstract:

"Accepted 1 December 2004) A numerical simulation of the aircraft impact into the exterior columns of the World Trade Center (WTC) was done using LS-DYNA. For simplification, the fuselage was modeled as a thin-walled cylinder, the wings were modeled as box beams with a fuel pocket, and the engines were represented as rigid cylinders. The exterior columns of the WTC were represented as box beams. Actual masses, material properties and dimensions of the Boeing 767 aircraft and the exterior columns of the WTC were used in this analysis. It was found that about 46% of the initial kinetic energy of the aircraft was used to damage columns. The minimum impact velocity of the aircraft to just penetrate the exterior columns would be 130 m/s. It was also found that a Boeing 767 traveling at top speed would not penetrate exterior columns of the WTC if the columns were thicker than 20 mm."

My immediate issues with this:

1. The 2 high bypass turbofan engines were highly energetic rotating complex physical shapes ( E_rot = 1/2 * I * omega^2), NOT rigid cylinders. The complicated moment of inertia and subsequent collision dynamics are likely very different than that of a simple cylinder (and I didn't see whether the rigid cylinder model was hollow or solid either).

2. I recall the perimeter columns being structurally modified with 4 external "ribs" to resist wind load bending, NOT simple box beams, which are generally more prone to crushing, twisting, and bending. The "trapeziodal" taper in the 47 core columns, in addition to their considerable thickness, likely compensated for box beam limitations.

http://911research.wtc7.net/wtc/arch/perimeter.html

From:

http://www.911research.com/papers/trumpman/CoreAnalysisFinal.htm

" In a 2004 presentation NIST asserts that the 47 core columns had a factor of safety of about 2.25. The 236 perimeter columns had a factor of safety of about 5.0 (it has been asserted that the higher factor of safety for the perimeter columns was to handle wind loads). It has been asserted that the core columns, the main load bearing columns, carried 60% of the building load, and the perimeter columns supported 40% of the building load. This was a big building, like a rock in Lower Manhattan for 30 years."

"The factor of safety is based upon the dead load (building materials) of the building and the intended live load (people, office furniture, and similar). The dead load of a floor was 1,818 tons. The floor area was rated 40-150 psf (1.9-7.18 kPa), depending on what the area was going to be used for. Higher load ratings generally were for areas that would support larger than normal loads such as mechanical equipment. Below are floor load estimates based on a review of WTC data contained in a 2005 NIST report. This report contained select scanned images of original WTC specification documents. Because of contradictions in the NIST final report this paper relied on the original WTC specification documents. Data was incomplete so inferences had to be made. The load rating for columns in the perimeter area was 50 psf. The load rating for the core area was up to 100 psf. This comes out to be an estimated 75 psf average for an office floor. The load ratings for floors 110-94 average out to be about 82 psf (3.9 kPa) per floor. On average, a floor's design live load was 1,488 tons. The estimated total weight of a floor, dead load plus live load, is 3,306 tons. Add the factor of safety and the building structure could handle multiple times this load. It is estimated that the average factor of safety for a floor was 3.35. This means a floor could handle a total of 11,075 tons before failing. To visualize, imagine 5,500 2-ton cars stacked in a square about 1/3 of a city block."

To reiterate: 236 perimeter columns at ~5.0 "safety factor"
47 core columns at ~2.25 "safety factor"

Also from the same on ASTM A36 steel:

"We need to account for weakening by heat. Earlier it was calculated that the average air temperature on a floor with fire was 148 C at the time of collapse. Using a general steel strength versus temperature chart, one finds that the steel would have lost about 2% of its strength if it was heated to this temperature. Adjusting our figure we get 466 MPa." "We also have to account for weakening by the plane impact. In a 2004 presentation NIST asserts from its "modeling" that in the "Realistic Case", 3 core columns were severed, 10 were damaged. In this same presentation the "Realistic Case" for the perimeter columns was 34 severed columns and 5 damaged."

dMole
12-17-2007, 10:50 AM
I found 2 more that have some good info (and considerable suspect info IMHO in a quick scan of them).

http://www.tms.org/pubs/journals/JOM/0112/Eagar/Eagar-0112.html

" To a structural engineer, a skyscraper is modeled as a large cantilever vertical column. Each tower was 64 m square, standing 411 m above street level and 21 m below grade. This produces a height-to-width ratio of 6.8. The total weight of the structure was roughly 500,000 t, but wind load, rather than the gravity load, dominated the design. The building is a huge sail that must resist a 225 km/h hurricane. It was designed to resist a wind load of 2 kPa—a total of lateral load of 5,000 t."

[Ed: I recall the wind at JFK being about 5mph at sea level around 09:00 on 9-11-2001. I haven't seen any data on winds aloft, but the smoke in the photos and videos indicates DAMN LITTLE.]

"Inside this outer tube there was a 27 m × 40 m core, which was designed to support the weight of the tower"

[Ed: Ummm, one "core", NOT 47 core columns- hmmmm... Also, the perimeter supported a lesser portion of "the weight of the tower"]

" The only individual metal component of the aircraft that is comparable in strength to the box perimeter columns of the WTC is the keel beam at the bottom of the aircraft fuselage. While the aircraft impact undoubtedly destroyed several columns in the WTC perimeter wall, the number of columns lost on the initial impact was not large and the loads were shifted to remaining columns in this highly redundant structure. Of equal or even greater significance during this initial impact was the explosion when 90,000 L gallons of jet fuel, comprising nearly 1/3 of the aircraft’s weight, ignited. The ensuing fire was clearly the principal cause of the collapse (Figure 4 (http://www.tms.org/pubs/journals/JOM/0112/Eagar/fig4.gif))."

[Ed: Where does the fuel number come from? What is so "clearly" about fire causing the collapse? Thermal data is where?]

-------------ARTICLE 2
http://www.tms.org/pubs/journals/JOM/0711/banovic-0711.html

" During the recovery effort after September 11, and before NIST began its collapse investigation, volunteers from FEMA, ASCE, NIST, the National Science Foundation (NSF), and the Structural Engineers Association of New York (SEAoNY) worked at the four steel recycling facilities to identify and collect steel members important to the investigation. They focused on identifying pieces that the aircraft struck or were obviously burned, as well as pieces from the fire and impact zone. The National Institute of Standards and Technology arranged to have these pieces shipped to its facility in Gaithersburg, Maryland."

[Ed: NO intact, uncompromised beams were focused on??? The article in the post above indicates that the vast MAJORITY of columns were not compromised. Also, exactly how do you get steel members to "burn?"]

" In all, NIST cataloged 236 structural steel elements:




Ninety exterior column panels, of which 42 were unambiguously identified. Of those identified, 26 came from the fire and impact floors, and four of these had been struck by the airplane that hit WTC 1.
Fifty-five core columns, of which 12 were unambiguously identified. Four of the identified columns came from the fire and impact zones.
Twenty-three pieces of floor truss. Unfortunately, these elements had no identifying marks, so their original location in the towers is unknown.
Twenty-five pieces of the channel that supported the floor trusses at the core; all are of unknown location."
[Ed: So 26/42 of the perimeter colums were impact/fire damaged, and 4/42 of those were "impact columns". But the earlier JOM article stated: "the number of columns lost on the initial impact was not large and the loads were shifted to remaining columns in this highly redundant structure". 4/55 core column sections were fire/imact damaged. The uncompromised?? steel was NOT focused on, and QUICKLY shipped overseas for "recycling," in conflict with typical crime-scene SOPs. Hmmm... I'll let the reader calculate his own percentages here]

" Although many of the individual recovered elements are rather large, the collection represents less than 0.5 % of the more than 200,000 tons of steel used in the buildings. It does include, however, representative samples of all the relevant steels necessary for estimating properties for the impact and collapse models. Given the difficulties in locating, identifying, and safeguarding elements in the field, the extent of the collection is impressive."

[Ed: take the 22/42 fire perimeter, 4/42 WTC1 impact perimeter, and 4/55 fire/impact damaged core percentages above and multiply by 0.005 to get a representative percentage of the fire/impact damaged steel actually recovered from the Towers- it is going to be QUITE small. I think the article meant "Given the difficulties in having your crime scene compromised and evidence shipped overseas for destruction, the extent of the collection is impressive." (But I'm just going from the observed facts from the last 6 years of federal "investigation" here). Were the investigating agencies picking steel evidence or cherries on Manhattan Island? My $0.02]


EDIT: 2 more UNREVIEWED articles at JOM:
http://www.tms.org/pubs/journals/JOM/0112/Marechaux/Marechaux-0112.html


http://www.tms.org/pubs/journals/JOM/0112/Biederman/Biederman-0112.html

dMole
12-17-2007, 11:01 AM
Here are a few links on the Boeing 787 composite fuselage testing (also has a little info on aluminum B757/B767 fuselages and "skins").

http://seattletimes.nwsource.com/html/boeingaerospace/2003612251_boeing111.html

http://seattletimes.nwsource.com/html/businesstechnology/2003612251_boeing111.html

" Why build a plastic jet?
http://seattletimes.nwsource.com/art/ui/dot_grey808080.gif
http://seattletimes.nwsource.com/art/ui/dot_clear.gif
Carbon-fiber reinforced plastic has advantages over aluminum:

Strong: Carbon fiber laid in precise configurations provides optimal strength where loads are heaviest.

Light: The plastic construction is up to 30 percent lighter than aluminum. Less weight means the plane burns less fuel.

Doesn't corrode or fatigue: Metal fatigues because of repeated stress over time, and it corrodes with exposure to moisture. Plastic does neither. [Ed: Aluminum metal fatigue? The MSM/OCT mentions this how often? Hmmm....]


Reduces maintenance: Without corrosion and metal fatigue, a 787 will require a full heavy-maintenance check every 12 years, Boeing estimates, compared with every six years for a metal jet such as the 767. [Ed: this maintenance check data for B757 & B767 is where exactly?]


Allows fabrication of huge pieces: A one-piece fuselage section replaces 1,500 sheets of aluminum and eliminates as many as 50,000 fasteners.

Nicer air, a better view for passengers: Boeing says it can keep the air that passengers breathe moister and more pressurized because the one-piece plastic fuselage sections are stronger, sealed more tightly and won't be damaged by humidity. The strength of the structure also allows bigger windows.

Source: Boeing

[Boeing 787 fuselage test- interesting comments]

http://boeingblogs.com/randy/archives/2007/09/testing_testing.html

http://seattlepi.nwsource.com/business/175791_composites01.html

dMole
12-17-2007, 11:33 AM
Some interesting articles on the 1945 B-25 bomber impact with the Empire State Bldg. in the fog:

http://www.tms.org/pubs/journals/JOM/0112/News/News8-0112.html

"At 9:40 a.m., as workers went about their business in the Catholic War Relief Office on the 79th floor, the B-25 crashed into that office at 322 kilometers per hour. The impact reportedly tore off the bomber’s wings, leaving a five meter by six meter hole in the building. One engine was catapulted through the Empire State Building, emerging on the opposite side and crashing through the roof of a neighboring building. The second engine and part of the bomber’s landing gear fell through an elevator shaft. When the plane hit, its fuel tanks were reported to have exploded, engulfing the 79th floor in flames.

The 102-story building shook with the initial impact, according to witnesses, but within three months, the damage was repaired at a cost of about $1 million. Smith died in the crash, along with two other crew members. Eleven workers died in the Catholic War Relief Office, and at least two dozen people were injured."

From:
http://www.withthecommand.com/2002-Jan/NY-empireplane.html

"It is believed that the planes speed at this time was 225 mph. Within seconds the plane was closing rapidly on the Empire State Building. Col. Smith attempted to veer away from the structure but his proximity to the building would not allow for such an evasive maneuver. The plane impacted the 78th and 79th floors on the towers north end.
The impact of the plane created an 18 x 20 foot hole in the side of the tower. This crash caused extensive damage to the masonry exterior and the interior steel structure of the building. The 102-foot building was rocked by the impact. Many people who were in the street at the time saw flames shooting from the point of impact, which was at the 913-foot level. The impact was heard as far as two miles away. Flames and dense smoke obscured the top of the structure. Later on a wing was found on Madison Avenue, one block away. http://www.withthecommand.com/2002-Jan/empire%201.jpg Nearby buildings were damaged by fragments of the impact and one of the planes engines was found on the South side of the building in the top of a twelve story building. The engine had flown over thirty-third St. and had crashed through a skylight in a penthouse."

From:

http://www.cosmik.com/aa-april02/dj82.html

"Colonel Smith banked away to the west just in time. How he got around the next few buildings is anybody's guess, but the one thing we do know is that despite his efforts to climb and bank away, he flew his plane, along with his two-man crew, into the north side of the 79th floor of the Empire State Building at 9:49 AM.

Inside the building there was only a small work force that day. On the 79th floor, in the offices of The National Catholic Welfare Service (now known as Catholic Relief Services), faith was put to a severe test as 11 workers were killed, some burned to death at their desks. The impact was thunderous, leading many, both inside and outside the building, to believe that New York City was being bombed. Debris was raining down from over 900 feet in the sky, much of it burning. Naturally, panic ensued.

http://www.cosmik.com/aa-april02/pics/dj4.jpg Back on the 79th floor, a fire was burning. The 78th floor was involved, as well, and there were other problems. On impact, the plane's fuel had exploded, sending a fireball down the side of the building and through the inside via hallways and stairwells. The fireball reached all the way to the 75th floor. One of the plane's engines, broken loose from the wreckage, shot through the building, tearing through several walls and finally out a south side window, finally coming to rest on the roof of a 12-story building across 33rd Street. Miraculously, none of the tragedy's victims were killed by the giant engine.

The saga of engine number two is just as dramatic. It, too, broke loose from the plane on impact, but instead of exiting the building it flew directly into an elevator shaft and on top of an elevator car, which began to fall rapidly with two terrified women inside. Even in 1945 elevators were equipped with hydraulic "slowing" devices for emergencies like... well, nobody ever dreamed of emergencies like this one, but for emergencies, nonetheless. When a rescue crew finally reached what was left of the elevator car at the bottom of the shaft, they were amazed to find living, breathing women with one hell of a story to tell their grandchildren.

Back on 79, surviving office workers would have sadder stories to tell their grandchildren. Two of the ladies from the office saw their supervisor, Joe Fountain, standing upright and still in the flames. They called to him and he eventually walked to them, but the damage had been done and he died just a few days later. They'd never shake that vision. Nobody who was near the Empire State Building that morning would ever be able to forget the sight of that burning plane wedged in the side of the building, the black billowing smoke partially obscuring the upper floors from view"


[Ed: yes this was a much smaller, slower propeller-driven aircraft and a "conventional" steel & masonry skyscraper. Let's consider what we do find though.

1. Two OF TWO engines survive and are torn off the aircraft, one penetrating all of the way through the building and flying across the street.
2. A section of wing is torn off and found a block away on Madison Avenue
3. The WTC Towers were an "open" floor plan, increasing the probablity that at least ONE of the two the UA175 WTC2So engines should have penetrated through the Tower, with the starboard engine being very close to the perimeter columns.
4. Not even partial building collapse with 4 floors of aircraft fuel fire.]

dMole
12-17-2007, 11:50 AM
[Ed: take the 22/42 fire perimeter, 4/42 WTC1 impact perimeter, and 4/55 fire/impact damaged core percentages above and multiply by 0.005 to get a representative percentage of the fire/impact damaged steel actually recovered from the Towers- it is going to be QUITE small.

Late EDIT: Make that 26/42 fire perimeter, ... above

psikeyhackr
12-21-2007, 11:47 PM
I researched the B-25 a little and some place said the stall speed was 130 mph. I have always heard that story as their being lost in the fog so I figured if the stall speed was 130 they would have been going slower than 200.

psik

dMole
12-24-2007, 08:44 PM
Upon closer inspection, 2 of the moderately-informative articles that I posted above were authored by NIST and MIT personnel.

Hmmmmm.....

dMole
01-03-2008, 05:13 AM
Hi Psik,

I've been searching for WTC Finite Element Analysis (FEA) simulation information lately. :dilbert: I'd prefer to not peruse the NIST report again right now, but here's who landed the simulation/consulting NIST contracts:

http://wtc.nist.gov/solicitations/

I found these gems over at MSC.Software, who did the FEMA/ASCE/NSF Finite Element Analysis (FEA) animation/study:

-----BEGIN QUOTED
CREATING THE MODEL
Because of the limited time available to provide an initial
analysis, a search of MSC.Software’s past projects turned up
the public domain geometry of a Boeing 747 with partially
meshed wings and engines. MSC.Patran was used to add the
fuselage and stiffeners, tail section, flooring and other major
components, completing the finite element model of the B747.
Concentrated masses were added in specific locations along
the aircraft to represent the cargo, passenger weight
distribution and fuel. The total weight of the aircraft was
304,000 kg.
A full mockup of the building was unnecessary, because of
time limitations and the actual structural data had not yet been
made available. Therefore, a generic six-story steel structure
was constructed with tubular beams and columns. The gravity
loading was applied to the entire structure and the dead weight
of the building was added through the floorings located on the
top-two and bottom-two floors of the structure. Floors were
not added to the impact area, which facilitated the study of the
failure pattern of both the aircraft and the beam-column
connections. The foundation of the building was rigidly fixed.
Approximately 61,000 elements were used to construct the
entire model of the building and B747.
-----END QUOTED
http://www.mscsoftware.com/support/library/wp/pdf/wtc_collapse.pdf

I'll let you count the problems in the two paragraphs above.

Also, there may be something helpful in these NIST papers from j911s (but I've only read a few of them so far, but I found some information on the NIST simulations):

http://www.journalof911studies.com/volume/200704/SzambotiSustainabilityofControlledDemolitionHypoth esisForDestructionofTwinTowers.pdf

http://www.journalof911studies.com/volume/200612/NIST-WTC-Investigation.pdf

http://www.journalof911studies.com/volume/200704/NISTandDrBazant-SimultaneousFailure-WTCCollapseAnalysis2.pdf

http://www.journalof911studies.com/volume/200704/RFCtoNISTbyMcIlvaineDoyleJonesRyanGageSTJ.pdf

http://www.journalof911studies.com/volume/2007/NISTresponseToRequestForCorrectionGourleyEtal2.pdf

[Ed: NIST says "Blame it on Taguchi/Design of Experiments"]
http://www.journalof911studies.com/volume/2007/AppealLetterToNISTGourleyEtAl.pdf

December 2007 papers
http://www.journalof911studies.com/volume/200703/GUrich/MassAndPeWtc.pdf

http://www.journalof911studies.com/volume/200703/Sudden_collapse_initiation_impossible.pdf

I'm not betting that you've heard back from Purdue yet.

psikeyhackr
01-04-2008, 03:23 PM
Floors were not added to the impact area, which facilitated the study of the failure pattern of both the aircraft and the beam-column connections. The foundation of the building was rigidly fixed. Approximately 61,000 elements were used to construct the entire model of the building and B747.
I'll let you count the problems in the two paragraphs above.

ROFLMAO

I'm content to stop at two because they are so BIG.

One relates directly to my model.

Years ago I read someone claiming that the impact energy of the plane was 95% of the maximum wind force the building was designed to handle. But the wind doesn't do localized structural damage to a skyscraper, it causes the whole thing to sway.

But the energy of the plane impact affected the towers in two ways. Localized damage and oscillation of the entire building. I have always wondered how they separated those two, the more of one the less of the other. So if they ran the simulation with those few floors and a rigid foundation they would get a lot more impact damage from the simulation than actually occurred.

Also without floor slabs the perimeter columns would bend more and the fuselage and wings wouldn't get sliced and diced by the concrete and trusses of the floors and probably hit the core harder.

Sounds like a delusional simulation to me.

So it is back to my distribution of mass business. That info plus the amount of movement of the building would be necessary to compute how much kinetic energy just rocked the entire building and how much did damage.

Thanks dMole

psikey

PS - It sure is a pain having to do so much work just to find people are talking BULLSHIT!

dMole
01-06-2008, 04:44 PM
Psik,

I've had a few more thoughts on this.

1. How do we know that the passenger mass was DIRECTLY coupled to the airplane's momentum? Do we know the seat belts were on and tight? Weren't the pilots and some passengers injured/bleeding/dead in the "back of the plane" according to the "phone calls?" There is also considerable question about gate assignments and the actual passenger count over at Pilotsfortruth.org.

2. I'm pretty certain that the 110-story towers were on seismic mounts (like the skyscrapers in Japan). Seismic (and their smaller cousins, kinematic) mounts ARE NOT stationary. These are loosely related to gyroscopic systems and the "Steadicam" used to dampen movie camera oscillations.

3. A 1000+ foot long intermediately-loaded cantilevered beam (vertical skyscraper) does what exactly when a [impulse] driving force is applied? You've already alluded to this quite well in your physical model, I believe. Yours is the only physical model that I've seen, by the way. It does look like NIST did some questionable, overly-aspirated "fire experiments" from what I read of the papers linked above.

http://www.efunda.com/formulae/solid_mechanics/beams/casestudy_display.cfm?case=cantilever_interload

http://www.efunda.com/formulae/solid_mechanics/beams/casestudy_bc_cantilever.cfm

4. We might be able to glean something from the seismic data- I haven't looked at that for a few years.

d

psikeyhackr
01-07-2008, 10:09 PM
1. How do we know that the passenger mass was DIRECTLY coupled to the airplane's momentum? Do we know the seat belts were on and tight?

I have heard that people can be cut in two by seat belts in automobile accidents. I don't think seat belts would matter when decelerating from 500 mph to ZERO in 200 feet or less.

If the planes were switched wouldn't the flight crews of 175 and 11 have to be in on it?

psik

dMole
01-21-2008, 02:01 AM
Hi psik,

Here's a link to what I meant on AA11 at least. Apparently, there were either 2 AA11's leaving Boston Logan, or it left 2 different gates.

http://z9.invisionfree.com/Pilots_For_Truth/index.php?showtopic=37&view=findpost&p=1444460

There are likely some other anomalies that I haven't located yet...

psikeyhackr
01-24-2008, 05:46 PM
There are likely some other anomalies that I haven't located yet...
Well there is certainly no shortage of anomalies on 9/11.

http://drjudywood.com/articles/JJ/

http://www.weourselves.org/mp3/wpfw_011408_andrew-judy1.mp3

http://www.weourselves.org/mp3/wpfw_011408_andrew-judy2.mp3

http://www.weourselves.org/mp3/wpfw_011408_andrew-judy3.mp3

http://www.weourselves.org/mp3/wpfw_011408_andrew-judy4.mp3

http://www.weourselves.org/mp3/wpfw_011408_andrew-judy5.mp3

http://www.weourselves.org/mp3/wpfw_011408_andrew-judy6.mp3

psik

dMole
01-24-2008, 07:08 PM
I'm agnostic on Judy Wood (and most other things I don't know firsthand), but I'll try to listen to the MP3s if I get time.

I do know she is rather taboo in most 9/11TM circles however.

d

psikeyhackr
01-25-2008, 04:44 PM
I mostly try to focus on the impossibility of an airliner causing what happened to the WTC. But I have looked over those pictures of the cars and am forced to admit that nothing I know of could produce those effects.

So we end up with people talking about nukes and the "impossibility" of wiring the building which I'm not sure is impossible. And ignoring tons of debris hurled 600 feet into the AmEx Tower. FEMA has an X on the map for it but doesn't tell us what it weighed. It had to be at least 80 tons.

So whatever the truth is, it is lost in the confusion and bullshit.

psik

dMole
01-26-2008, 03:01 PM
Agreed, the "inverse square" law doesn't jive with the auto and truck destruction, and the only 2 explanations that have been offered are taboo subjects apparently. That is a LOT of heat a LONG way from the burning Towers, no doubt. Maybe all that indestructo-paper blowing around somehow transferred that heat to the police cars, ambulances, and fire trucks and blew out the nearby windows... or not.

How about 2 Solid State Cockpit Voice Recorders (SSCVR) and 2 Solid State Flight Data Recorders (SSFDR) that are data-survival rated for 3400G impacts and 1100 degrees C for 60 minutes ALL being vaporized on the same morning by two 1G building collapses?

I'm glad physics doesn't work like that on THIS side of the Rockies...

psikeyhackr
02-10-2008, 12:49 PM
I just had a peculiar thought yesterday. It is related to the computation of the heat energy necessary to weaken the steel. It is discussed on this page:

http://911research.wtc7.net/mirrors/guardian2/wtc/how-hot.htm

The airliner added more than 100 tons to the mass of the building, mostly aluminum. The fire can't tell what is part of the building and what isn't so the wreckage of the plane would absorb heat also. But energy absorbed by the wreckage would not weaken the building so the energy and temperature calculations would have to include a heat sink that big.

I don't recall seeing any mention of this in six years.

psik

dMole
02-16-2008, 09:14 PM
That's a very good point. "Thermal mass" is a concept understood by few, and a Boeing transport airliner will bring a LOT of it to the party. Have you ever sat on aluminum football stadium bleachers in early winter? For simplicity's sake let's just call it aluminum mass * the specific heat of aluminum (in applicable units). Let's subtract out the engine masses, since they have very little aluminum and are quite hot already.

From my records, AA11 was reported to be:
B767-223ER #N334AA Boeing# 22332, GE CF6-80A2, Mode 3A 1443 off 08:20:38 EDT

From GE:
http://www.geae.com/engines/commercial/cf6/cf6-80c2.html

Fan/Compressor Stages: 1F/3LPC/14HPC
Low-Pressure Turbine/High-Pressure Turbine Stages: 5/2
Max Diameter (Inches): 106
Length (Inches): 168

Dry Weight (Lb.): 9,480 - 9,860

Okay, let's average the engine at 9670 lbs. 2 of these are 19,340 lbs. Let's not be morbid and consider the passenger specifics, but the Jet A thermal mass also should be considered in a better estimate.

From:
http://www.airliners.net/info/stats.main?id=103

767-200ER - Empty with PW4056s 76,566kg (168,800lb), with CF680C2B4s 76,476kg (168,600lb), operating empty with PW4056s 84,415kg (186,100lb), with CF680C2B4Fs 84,370kg (186,000lb). Max takeoff with PW4056s or CF680C2B4Fs 175,540kg (387,000lb).

From:
http://www.janes.com/aerospace/civil/news/jawa/boeing_767.shtml

"Structure
Fail-safe structure. Conventional aluminium structure augmented by graphite ailerons, spoilers, elevators, rudder and floor panels; advanced aluminium alloy keel beam chords and wing skins; composites engine cowlings, wing/fuselage fairing and rear wing panels; CFRP landing gear doors; and aramid flaps and engine pylon fairings.
Subcontractors include Boeing Military Aircraft (wing fixed leading-edges); Northrop Grumman (wing centre-section and adjacent lower fuselage section; fuselage bulkheads); Vought Aircraft (horizontal tail); Canadair (rear fuselage); Alenia (wing control surfaces, flaps and leading-edge slats, wingtips, elevators, fin and rudder, nose radome); Fuji (wing/body fairings and main landing gear doors); Kawasaki (forward and centre fuselage; exit hatches; wing in-spar ribs); Mitsubishi (rear fuselage body panels and rear fuselage doors). "

All right, fuel will come out of the maximum takeoff weight- let's ignore it though. If we take off 2 engines 186,000 - 19,340 = 166,660 lbs. Let's assume 80% of this figure is aluminum, since most of those other aerospace materials are quite light and most of the structure is aluminum. This gives 133, 328 lbs of aluminum for AA11/North Tower WTC1.

From
http://hyperphysics.phy-astr.gsu.edu/Hbase/tables/sphtt.html

Specific heat of aluminum (c_Al) = 0.215 BTU/lb * deg_F = 0.900 J/g*K = 24.3 J/mol*K

So, the thermal mass would be 133,328 lb * 0.215 BTU/lb * deg_F = 28665.52 BTU/deg_F. Now thermal coupling is fairly tricky business, but as you pointed out, aluminum is used extensively for its "heat sink" properties. The NIST FAQ #7 claims a maximum air temp of 1800 F, but let's use the melting point of aluminum instead here.

http://www.chemicalelements.com/elements/al.html
Melting Point: 660.37 °C (933.52 K, 1220.666 °F)

Okay, let's assume we heat the thermal mass above from 70F to 1221 F, or +1151 deg_F. 28665.52 BTU/deg_F * 1151 deg_F = 32994013.52 BTU = 3.30E7 BTU to melt AA11. That's 33 million BTU's of heat for just AA11.
------
My records for UA175 show:
B767-222 #N612UA Boeing # 21873, PW JT9D-7R4D, Mode 3A 1470 > 3020 > 3321

I don't really like Wikipedia, but they came up first for the JT9's:
http://en.wikipedia.org/wiki/Pratt_%26_Whitney_JT9D

JT9D-7R4D/D1
8905 lb, 132.7 in long, 93.4 in diameter fan, 48 000 lbf Static Thrust

From the page above:
http://www.airliners.net/info/stats.main?id=103

" 767-200 - Empty with JT9Ds 74,752kg (164,800lb), with CF6s 74,344kg (163,900lb). Operating empty with JT9Ds 80,920kg (178,400lb), with CF6s 80,510kg (177,500lb). Max takeoff 136,078kg (300,000lb), medium range max takeoff 142,881kg (315,000lb)."

178,400 - (2 * 8905) = 160,590 lb. Again assuming 80% Al, this gives 128,472 lbs of aluminum.

128,472 lb * 0.215 BTU/lb * deg_F = 27621.48 BTU/deg_F for UA175/WTC2 South.

27621.48 BTU/deg_F * +1151 deg_F = 31792323.48 BTU = 3.20E7 BTU to melt UA175. That's 32 million BTU's. I think psik and now I are the first to even look at these considerable heat sinks that I'm aware of.
-------------------------------------
But wait, there was WATER in those buildings for sprinklers and restrooms, etc. I even recall hearing of water tanks to maintain pressure. Now I think nearly everyone knows that automobile engines usually use water for cooling, although they may not be aware of its extremely high specific heat capacity.

From:
http://www.sciencebyjones.com/specific_heat1.htm

Relative to aluminum, water has a specific heat capacity of 1.00/0.217 = 4.6082949309 times.

Relative to steel:
http://www.ac.wwu.edu/~vawter/PhysicsNet/Topics/Thermal/HeatCapTable.html (http://www.ac.wwu.edu/%7Evawter/PhysicsNet/Topics/Thermal/HeatCapTable.html)

1.00/0.108 = 9.2592592593 times higher for water than steel.

Looking at aluminum's thermal conductivity,
http://hyperphysics.phy-astr.gsu.edu/hbase/tables/thrcn.html

it is 205.0/50.2 or 4.0836653386 times that of steel. Relative to concrete, 205.0/0.8 =256.25 times. It is 205.0/0.6 or 341.6666666667 times that of water at 20 deg_C.

Okay, for the laymen out there, this says the majority of the heat will likely flow to aluminum first (and melt it if hot enough), then steel, then concrete, then water.

Even the NIST FAQ says:
http://wtc.nist.gov/pubs/factsheets/faqs_8_2006.htm
"8. We know that the sprinkler systems were activated because survivors reported water in the stairwells. If the sprinklers were working, how could there be a 'raging inferno' in the WTC towers?

Both the NIST calculations and interviews with survivors and firefighters indicated that the aircraft impacts severed the water pipes that carried the water to the sprinkler systems. The sprinklers were not operating on the principal fire floors.

However, there were ample sources of the water in the stairwells. The water pipes ran vertically within the stairwells. Moreover, there would have been copious water from the broken restroom supply lines and from the water tanks that supplied the initial water for the sprinklers. Thus, it is not surprising that evacuating occupants encountered a lot of water.

..."

Now while the water is much less thermally conductive, I don't think that the incredible thermal mass of an unknown "bath" of water can be ignored in a proper accounting of WTC heat sinks. I haven't even mentioned the high heat of vaporization of water, but I think anyone who has boiled a pan of water knows what I'm getting at here.

There is also some interesting info about water and fuel tanks over at:
http://www.whatreallyhappened.com/fema_report.html

d
------------------------------------------
EDIT: Well this was interesting- haven't seen it before...

http://www.epa.gov/oig/reports/2003/wtc/nycdeppn20010916.htm

Supplemental Appendices
Report No. 2003-P-00012

* This document was reproduced to maintain Accessibility requirements as outlined by Section 508. If you would like to obtain a printed version of this document please contact the OIG's Office of Congressional and Public Liaison at (202) 566-2391.
PUBLIC NOTICE

September 16, 2001
CONTACT: (718/337-4357)

Notice to Building Owners Located South of 14th Street, Manhattan

Building Maintenance Issues Involved in Reopening Buildings Closed Since 9/11/01

Air Circulation Systems: Building owners are advised that air circulation systems not operated since Tuesday must have their filters replaced before the system is restarted. Systems should be run on a recirculated air setting and not on fresh air, if possible, until the WTC fire is extinguished.

Asbestos or other Hazardous Materials situations: Owners/managers should have possible contamination problems, indoors or at roofs, reviewed by competent professionals (i.e., R.A.s, P.E.s, Asbestos Inspectors, etc.) prior to beginning clean-up of buildings with maintenance personnel. Where no problems are noted, proceed with clean-up. Where problems (i.e., HazMat) are noted, contact DEP as indicated below.

All issues regarding air asbestos and/or hazardous material clean-up should be directed to the Department of Environmental Protection's complaint center at 1-718 DEP-HELP (337-4357). Help center operators will refer your call to Asbestos and Hazardous Materials staff from 8:00 a.m. to 8:00 p.m. every day including weekends until such time as the Mayor's office declares the emergency over. Staff will review each case individually on the telephone and verbally approve clean-up activities--paperwork to follow. Emergency situations which arise outside of these time frames will be handled by help center staff taking down the caller's name and contact phone number and notifying personnel on stand-by who will then contact the caller directly.

Open Water tanks: Building owners are advised that water tanks not operated since Tuesday must be completely drained from the cellar, flushed, cleaned, refilled and plumbing systems flushed before having the building reoccupied. You should contact the water tank cleaner who normally performs this yearly operation for you to arrange for this cleaning, if possible.

All other water pressure, sewage, noise and air quality complaints should be directed to 1-718-DEP-HELP.

AuGmENTor
02-16-2008, 10:23 PM
Da?

dMole
02-17-2008, 01:09 AM
Thanks Aug. You made me notice that I hadn't finished my homework. To actually MELT the aluminum into the liquid phase, I'd need the heat of fusion figured in too.

http://www.engineeringtoolbox.com/fusion-heat-metals-d_1266.html

Lists the heat of fusion for aluminum as 398 kJ/kg, or about 171.11 BTU/lb. For UA175, the "smaller" of the two calculations above, this adds 22 million BTU's, for a total of 54 million BTU's needed to melt the aluminum UA175 "heat sink." A BTU is the amount of heat needed to raise 1 lb of water 1 deg_F.

In other words, 54 million BTU's would heat 1,080,000 lbs (or approx. 135,000 gallons) of water +50 deg_F.

psikeyhackr
02-17-2008, 02:09 PM
ROFLMAO

dMole you are a trip.

It just gasses me how the NCSTAR1 report is full of so much trivia and they don't mention so much stuff likely to be important. They said one plane had 5 tons of cargo and the other had 9. Don't forget to put that in your calculations. LOL

But I did a search on "center of gravity" and it was not there. Then I searched on "center of mass" and found 4 mentions. Now I was thinking about the center of mass of the top portion of the building that supposedly crushed everything below. I was wondering how they could explain it staying centerd and not falling off the side. But they only talked about the "center of mass" of the plane in one report on the effect of the impact on suspended ceilings.

The whole building collapsed because of suspended ceilings. LOL

psik

psikeyhackr
02-25-2008, 03:41 PM
It's been close to a year since I payed attention to this but they did use "center of gravity" six times. But they weren't talking about real objects from 9/11.

The NIST NCSTAR1 report can be extremely amusing at times if you can stomach it. One of the most astounding events of 9/11 was the top of the south tower tilting before coming down and disappearing in a dense cloud of dust. So I figured any discussion of that occurence had to refer to either the "center of mass" or "center of gravity" of at least 25 stories of the building. So I searched my DVD download of the report to see what turned up. Definitely not what I expected.

Center of mass is only used 4 times and the only real object it references is the airplane. It appears that they were extremely concerned about ceiling tiles and devoted an entire report to them. The only Interesting thing about it that I can tell is that the plane decelerated at 60 g's and came to a stop in 0.63 seconds. Suspended ceilings must be of major concern in the collapse of a 500.000 ton building.


NCSTAR 1-5D Ceilings.doc (offset 34)
http://wtc.nist.gov/NISTNCSTAR1-5D.pdf
Reaction of Ceiling Tile Systems to Shocks

center of mass page 77(*3)

Some of the airplane debris would not likely have traveled this far into the tower, while some parts of the plane and some of the fuel passed through the building and exited the far side. It was, therefore, assumed that the center of mass of the airplane penetrated slightly more than one-half of the tower’s depth. Assuming that the center of mass of the airplane is located at approximately the center of its length, the center of mass of the airplane would have traveled approximately 197 ft (60 m) between when the nose impacted the face of the tower and when the airplane remnants came to rest.

center of mass page 79

where, x p (t ) was the position of the center of mass of the airplane at time t. Given the initial and final velocities of the airplane and the differential displacement, described above, Equations 2–3 and 2–4 were solved to determine the acceleration parameters. The estimated peak acceleration of the airplane was found to be –62g (–610 m/s2), and the estimated duration of the impact was found to be 0.63 s. The resulting acceleration history is shown in Fig. 2–45.

They don't use the term "center of gravity" in relation to any real physical object at the WTC. They only use it in explaining how they configured their simulation software in specifying columns for the simulator. I find this truly amazing for a 11,305 page report that took 3 years. I guess the centers of mass and gravity don't matter for the tons of material that was hurled hundreds of feet from the buildings.

NCSTAR 1-6.doc (offset 82)
http://wtc.nist.gov/NISTNCSTAR1-6.pdf
Structural Fire Response and Probable Collapse Sequence of the
World Trade Center Towers

center of gravity page 182

Shell elements were used to model the plates comprising the box column and the spandrels. Rigid elements connected the center of gravity of the column to its component plates and the spandrel at both the top and the bottom of the model. The column was simply supported in three directions at the bottom and simply supported in the horizontal directions at the top. Increments of axial displacement were applied at the top of the model.

center of gravity p186

In the ANSYS panel model, beam elements replaced shell elements to model the columns, while shell elements were used to model the spandrels, and beam elements attached the center of gravity of the columns to the mid-plane of its corresponding spandrel component at each shell element through the depth of the spandrel.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - -

NCSTAR 1-6C.doc (offset 48)
http://wtc.nist.gov/NISTNCSTAR1-6C.pdf
Component, Connection, and Subsystem Structural Analysis

center of gravity page 44

Four-node finite strain shell elements were used to model the plates of the column and the spandrels. Nodes of column plates at the top and the bottom of the model were rigidly tied to the center of gravity of the column cross section. The column was pinned at the bottom and fixed in the two horizontal directions at the top. Increments of axial displacement were applied at the top of the model at room temperature and 700 ̊C.

center of gravity page 216

The model also represented Column 151 from Floor 96 to Floor 97 since the dimensions, plate thicknesses, and material properties were identical to those of Column 151 from Floor 95 to 96. SHELL181 plate elements modeled the plates of columns and spandrels. CERIG rigid elements connected the center of gravity of the column to its component plates and to the spandrel at both the top and the bottom of the model. The column was pinned at the bottom and restrained in the two horizontal directions at the top. Axial displacement was applied incrementally at the top of the model.

center of gravity page 222

To capture the gravity load effects from upper floors (those above Floor 99), internal forces and moments at midheight of the columns between Floors 99 and 100 in the LERA SAP2000 global model, caused by dead plus 25 percent of design live load, were applied as loads at the tops of the corresponding columns in the exterior wall model at the center of gravity of the columns. To capture the gravity load effects from individual floors, floor loads were extracted from the LERA SAP2000 floor model and applied to each column.

center of gravity page 222

For columns that were modeled by BEAM189 elements, temperatures were provided for nodes at the center of gravity of the column, and their linear gradients transverse to the exterior wall were also provided. Gradients parallel to the wall were found to be negligible. Temperatures for SHELL181 elements were provided at each node. NIST did not always provide temperatures for the bolts at column splices. When bolt temperatures were provided, they matched temperatures at the nearest interior or exterior tips of columns.

All of the page numbers refer to the PDF pages, not the official NIST page numbers. Doing searches in Adobe shows the PDF numbers. I specified the offset for each report for the pedantic among us. Just subtract the offset from the PDF page to get the official government sanctioned, approved and certified page number.

Since for some reason the government locked this PDF document, even though taxpayers payed for it, it is impossible to cut and paste from it with Adobe. But never fear, I am much to lazy to have typed the info and was able to cut and paste from it with the Linux software, Evince.

psik

psikeyhackr
03-15-2008, 01:23 PM
The 9/11 Truth Movement has gotten extremely complicated and confusing with all of the different perspectives and interpretations of vast amounts of data resulting from the bizarre events of that day. Some of which is neither correct nor important, so inevitably a lot of people dismiss the movement as a bunch of kooks which, unfortunately, some of them are.

So I propose a little thought experiment to simplify things a bit.

Imagine that we have WTC2, the south tower, intact as it was on Sept 10, 2001. Since the plane impacted at the 81st level of the building let's completely remove FIVE LEVELS of the building, 79, 80, 81, 82 and 83. Since each level of the building was 12 feet in height this would leave a 60 foot gap between the top of the 78th level and the bottom of the 84th.

Now that is far more damage than the airliner could possibly do. It eliminates any debate about how hot the fires were and whether they could weaken the steel. Obviously there is not point in discussing fake planes.

The formula for distance from acceleration and time is:

d = 1/2 a t^2

Since gravitational acceleration is 32 ft per seconds squared the data for this problem yields:

60 = 16 * t^2

Therefore the time is about 2 seconds.

1.936491673 sec = t

So the intact upper 27 levels would take 2 seconds to fall and impact the intact lower 78 levels. The formula for velocity from acceleration and time is:

v = a * t

Which for these values yields:

64 ft/sec = 32 ft/sec^2 * 2 sec = 44 mph

Since each level of the World Trade Center was 12 feet the top of the 78th level was:

78 levels * 12 ft/level = 936 ft

Now if the falling 27 stories could maintain a constant velocity from the moment of impact until it reached the ground it is easy to compute how long that would take.

936 ft / 64 ft/sec = 14.625 seconds

If the bottom 78 floors prevent the top from accelerating but crumple at a constant velocity it would take 15 seconds to crush 78 floors. Since the building came down in 11 seconds the top had to crush the bottom and accelerate at the same time. A truly amazing feat.

Are we supposed to believe those 78 level would not cause the falling mass to SLOW DOWN?

What is going to happen the instant the instant the bottom of the 84th level comes in contact with the top of the 78th? They are going to engage in a mutual crushing of steel, concrete and office furniture that would be deadly to behold. But where is the energy to do that crushing going to come from? It is going to come from the kinetic energy of the falling mass. Which means the falling mass is going to SLOW DOWN. It is going to DECELERATE. It is going to undergo NEGATIVE ACCELERATION. Which means it must take longer than 15 seconds to reach the bottom, if it ever does.

But to come up with anything vaguely resembling an accurate analysis of this simplified thought experiment we would have to know the TONS of STEEL and TONS of CONCRETE on every level of the WTC. The expected and maximum loads for each level would probably help too. That would tell us how over-engineered the building was and the extra energy necessary to crush it. Since the people who designed the World Trade Center way back in the 60's, when computers still had CORE MEMORY, it is certainly amazing that our EXPERTS don't even raise such childishly simple questions in these days of laptop supercomputers. The NIST report mentions that total amount of steel in the towers three times but NEVER SPECIFIES the total amount of concrete though it says two types of concrete were were used.

Some people accuse the "conspiracy theorists" of not understanding the difference between static loading and dynamic loading as though the difference is going to cause the overloaded material to burst into dust. But we are dealing with a material state with inputs applied and a known output of a TOTALLY DEMOLISHED BUILDING. The known input is a 150 ton plane with 34 tons of kerosene traveling at 500+ mph. How can we claim to know the state of the material if we don't know the TONS of STEEL and TONS of CONCRETE on every level. The believers in the official story demand proof of an energy input besides the plane but don't demand accurate information about the subject of the destruction. You can't do an analysis if you don't know what you are analyzing.

Of course we can trust Dr. Sunder of the NIST when he says the buildings came down so fast because they were 70% air. It is incredible that the nation that put men on the moon will tolerate crap like that.

http://www.pbs.org/wgbh/nova/wtc/cons-flash.html

So until we can get such simple information as the TONS of STEEL and TONS of CONCRETE on every level then talking about fake planes, beam weapons and nuclear devices is absurd because we really don't understand what it was that was destroyed.

psik

psikeyhackr
04-07-2008, 12:24 PM
Dr Sunder of the NIST tells us that the World Trade Centers came down so fast because they were 70% air by volume.

http://www.pbs.org/wgbh/nova/wtc/cons-flash.html

Notice he specifies "by volume." So how much was that by weight? We often hear the each tower was 500,000 TONS. How many TONS of air were in the building?

1 cubic foot of air at standard temperature and pressure assuming average composition weighs approximately 0.0807 lbs.

These were the dimensions of the WTC

207 ft. * 207 ft. * 1360 ft. = 58,274,640 cu. ft. above ground volume of WTC

So that volume of air weighed:

58,274,640 * 0.0807 = 4,702,763.448 lbs. of air

Which came to:

4,702,763.448 lbs. of air / 2,000 lb/ton = 2,351.381724 tons of air

2,351.381724 tons of air / 110 levels = 21.38 tons of air per level

But obviously Dr. Sunder is saying that 30% of the building was not air.

21.38 tons of air per level * 70% = 14.96 30% loss due to presence of building

So there were approximately 15 tons of air on each level of the WTC but the NIST cannot tell us the TONS of STEEL and TONS of CONCRETE that were on each level of a building designed in the 1960s and stood for 28 years. They can't do that with 3 years of research and $20,000,000 but they can tell us it came down so fast because it was 70% air by volume. Well it was only 0.5% air by weight and it wasn't the air that held it up for 28 years.

On average the towers had 862 tons of steel on each level and he is saying they came down so fast because of 15 tons of air per level.

Dr. Sunder should be laughed all of the way back to India for saying something that ridiculous.

psik

dMole
04-25-2008, 04:56 PM
Dr Sunder of the NIST tells us that the World Trade Centers came down so fast because they were 70% air by volume.

Hi psik,

Well, I can think of one way that 70% air could lead to a "collapse" in a relatively-airtight container:

Add a vacuum source to cause a true "[b]implosion" [a misnomer all too often used in the 911TM to carelessly describe CD/engineered explosions], to quickly get rid of the 70% air .

Of course the only way I can quickly see to get one of [b]those of WTC tower dimensions is a thermobaric or "vacuum" bomb, and that doesn't exactly help Dr. Sunder's case now does it? Oh well, 70% air is [b]NIST's conspiracy theory, NOT mine.

http://en.wikipedia.org/wiki/Thermobaric_weapon

Anyway, in this case the potential energy (PE) of the implosion would be equal to the work done (W) [which would equal the negative definite integral of P dV, taken from V_initial to V_final], with P being pressure and V being volume, but you probably already knew this, I suspect. ;)

psikeyhackr
05-06-2008, 12:27 PM
Anyway, in this case the potential energy (PE) of the implosion would be equal to the work done (W) [which would equal the negative definite integral of P dV, taken from V_initial to V_final], with P being pressure and V being volume, but you probably already knew this, I suspect. ;)

LOL

Always with the techy jokes.

That makes sense but it hadn't crossed my mind actually.

psik

dMole
05-16-2008, 03:43 AM
Have fun kids...

http://youtube.com/watch?v=8vmIGGKvIms

Jeez AuG,

I think we've been there and done that already:
http://www.yourbbsucks.com/forum/showpost.php?p=89165&postcount=6

I've got a few Finite Element Analysis (FEA) videos that I could post here later that paint an entirely different picture. I don't think that anyone has released a copy of Christoph's (the guy with the accent in that video) or his boss' calculations and FEA source code from Purdue yet (2+? years later).

You've heard the saying "Garbage In, Garbage Out (GIGO)" haven't you?

Hell I've seen a video of Homer J. Simpson stopping a nuclear meltdown with his big muu-muu'ed ass...

AuGmENTor
05-16-2008, 08:42 AM
I didn't know it was t he same one. Sorry. Post withdrawn.

psikeyhackr
05-16-2008, 11:41 AM
I don't really see a problem with that Purdue video. We know a plane hit the building and had to do structural damage and start a fire. I don't see where it proves enough damage was done to start a collapse much less explain how that collapse could crush everything below.

But like my video shows some of the energy had to oscillate most of the buildings. The repeated impacts I did eventually caused a significant dent in the metal strip on the side of my model. So the energy applied to the WTC towers did that same thing as on my model. Some energy moved the structure and some energy damaged the structure. But in SIX YEARS I haven't heard anyone talking about separating those two energies to determine how much did structural damage.

psik

dMole
05-17-2008, 03:39 AM
Some energy moved the structure and some energy damaged the structure. But in SIX YEARS I haven't heard anyone talking about separating those two energies to determine how much did structural damage.

Chopped liver sez: I thought you and I have talked about that- or is it YEAR SEVEN now? ["You don't send me flowers.... anymore." JK- ;) ]

psikeyhackr
05-17-2008, 11:04 PM
Chopped liver sez: I thought you and I have talked about that- or is it YEAR SEVEN now? ["You don't send me flowers.... anymore." JK- ;) ]

OK, besides us. It is just that I jump around to a lot of websites that go on and on about this and a lot of these people just come across to me as smug assholes talking bullshit and I'm having a hard time not just going off and cursing people out.

I just had somebody on JREF tell me I wasn't taking gravity into account in my thought experiment (post #49). I was actually posting at Gregory Urich in relation to Bazant's paper.

I see we haven't mentioned Urich and Bazant here.

http://www.civil.northwestern.edu/people/bazant/PDFs/Papers/466.pdf

http://journalof911studies.com/volume/200703/GUrich/MassAndPeWtc.pdf

Other people have pointed out what I think is obviously wrong with what Bazant is saying.

http://www.911oz.com/vbulletin/showthread.php?t=155

So I am just boggled that this idiocy drags on and on. It passed ad nauseum for me some time last year. I must be delusional in thinking this whole thing should have been solved in less than 2 years.

psik

dMole
05-18-2008, 06:07 AM
Wow psik! You're either brave or foolish spending your valuable time "under the bridge" with those JREF trolls! Are my old friends mackay and Pat Curley (don't know his JREF username) still around over there? Ryan Mackey, Pat, and I go way back (I think "mackay" is allegedly from Scotland on another forum that I monitored, but I'm pretty sure Ryan Mackey is at NASA/JPL down in "The Armpit of LA" in SoCal, and I believe they are the same person based upon writing style and other observations). Is Pat "Yoda" Curley [long story] still trolling around as "Brainster" over at 911blogger? That guy needs to go screw a loose something in a BAD way IMHO...

Lately, I've taken to calling that place the Journal of Repugnant Egotistical Fluffers- based upon their sophist, rhetorical propaganda tactics and past behavior, I don't honestly consider this ad-hominem on my part anymore- it's just fact. I gave up even trying to be civil to that ilk months ago. Those OCT-apologist douchebags have earned my wrath the honest way- my hypothetical "gloves" would be OFF! I don't think they're worth any of our effort, however. Something about teaching a pig to sing...

I personally think they all ought to go smoke a big, fat JoREeFer and leave we C"T" "twoofers" alone, or get a more legal hobby, or take up knitting, or something... I don't go telling them what to believe or question both their sanity and their every word, then go pat the ad-hom backs of my "critical thinking" associates do I?

I suspect that you and I might have a slightly different definition of "critical thinking" than they do over there though. I'd say don't waste your intellect, energy, and sanity down in that cesspool.

"Strange" that JREF couldn't get any of their experts to the Month of Truth Week 3 debate over on Air America last Thursday. Ronald Wieck was the only OCT supporter on the show, and he nearly got thrown out for his repeated implications/aspersions that DRG is a liar- and that's about all that Wieck had. [CAUTION: I just got a .MIL security certificate notice at the following link. Hmmmm....] The show is at:

http://airamerica.com/clout/blog/2008/may/15/clout-month-truth-week-3?page=1

I'd advise you to swallow that JREF poison in small doses with large gulps of pure water... Here's a little tidbit that you might not have seen before:

James Randi pockets $175K while "non-profit" loses $80K in 2006. Hmmm...
http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=125x194011

Keep your head and hands inside the car at all times psik,
d

P.S. On the "didn't consider gravity" thing- it took me < 4 seconds (most of that scrolling up-thread) to find:

" Since gravitational acceleration is 32 ft per seconds squared the data for this problem yields:
60 = 16 * t^2"

Let's see PE = mass * height * WHAT AGAIN? JREF... Maybe they would have understood metric units better psik- HA HA!!:rolleyes:

psikeyhackr
05-18-2008, 01:27 PM
I didn't sign up for JREF until May 1st.

Someone who was impressed by them told me to check them out last June and I watched them for a while and concluded they were as you say. But I was told recently that Frank Greening was there so I registered in and made a comment about him. He challenged me on May 1st and I responded with my analogy using the stack of blocks.

He uses the handle Apollo20 and hasn't responded since then. ROFL

http://forums.randi.org/showthread.php?t=111647&page=8

I noticed this morning that the rating on my video went down from 4 stars to 3 stars though only 2 more people had rated it and no new comments were added. No one on JREF has commented on the video either. I provided the link a number of times. I guess these geniuses can't handle such simple physics.

R. McKey has said that no on has brought up the question of TONS of STEEL and TONS of CONCRETE on every LEVEL before. I find that very strange. I must be insane. My brain can't function with the physics of this distorted universe.

psik

dMole
05-18-2008, 03:53 PM
I didn't sign up for JREF until May 1st.
R. McKey has said that no on has brought up the question of TONS of STEEL and TONS of CONCRETE on every LEVEL before. I find that very strange. I must be insane. My brain can't function with the physics of this distorted universe.
psik
Yes, it's a strange soup made of cognitive dissonance, revisionism, bias, sophistry, poor understanding/manipulation of scientific laws, and flat out deception over there. That or else you "busted" them flat out, stone cold, and they finally fell silent.

I'm seeing your situation more often lately- the vaunted James Meigs of Pseudo Mechanics/Hearst Publications/History Channel now refuses to debate any subject related to 9/11 (he was invited to the radio debate last week).

I once saw a movie about the Civil War [can't remember the title] that ended with the cannon slowly falling silent across a smoky, bloody battlefield- bagpipe music wailing decrescendo into the distance while the scene fades to black. I'd like to think that all the "debunking" disinfo "guns" are soon to do the same. Are we finally reaching the 3rd Stage of Truth psik?

http://www.quotationspage.com/quote/25832.html

I'll leave you to hypothesize what exactly their motivations are over there- I've had my theories for some time...

So had you seen the $175,000 "Amazing Accounting" thing before?

Also, Kevin Ryan's refutation of R. Mackey's 200-page document is at:
http://www.journalof911studies.com/letters/b/MackeyLetter.pdf

Peace my intrepid compadre,
d

psikeyhackr
05-19-2008, 11:10 AM
Are we finally reaching the 3rd Stage of Truth psik?

Actually I am afraid we are approaching stage TWO.

I am inclined to wonder if the people that pulled this off anticipated the effect of the internet on the mass mind. It is like the printing press during The Reformation in Europe but every individual with a computer and a net connection is a printing press with a distribution network. Of course that means way more bullsh!t but ideas that make sense may stick with people more than anyone knows.

I really wish I could just go to an engineering school and read the minds of students. I think a lot of people are not saying what they are thinking because this is so weird. To my way of thinking this should be IMPOSSIBLE but I am obviously out of touch with reality. LOL

psik

dMole
05-22-2008, 01:05 AM
Hi psik,

I recommended this thread to an "anonymous unknown" from another board who said of our ongoing discussion:

" Gat Daym that stuff WAY above me!

I'll give you my thoughts tomorrow when I have a clear head.

Night,
xxxxxxxx"

I dunno if that's bad or good- but that's our "friendly" reviews...

psikeyhackr
05-24-2008, 09:22 AM
" Gat Daym that stuff WAY above me!
He was talking about the stuff you wrote.

LOL

psik

dMole
05-26-2008, 05:28 PM
Hi psik,

Have you seen the following Finite Element Analysis (FEA) video yet? I found it a while back, and it seems to be pretty rare. Usual disclaimer applies- I do NOT necessarily agree with or support EVERYTHING the author states or implies in the videos.

Thought I would bounce these off you for your take.

http://www.youtube.com/watch?v=ExmSMU9ls-w

http://www.youtube.com/user/mmmlink

psikeyhackr
05-26-2008, 09:01 PM
I couldn't handle the music in the 2nd one. Too much drama and excitement.

LOL

It is certainly sobering to think that the Empire State Building was completed in 1931 and there were no electronic computers until 1945. Of course when the WTC was designed the computers that were impressive at the time are a joke in terms of today's processing power. My Archos PMA400 that fits in my pocket

http://www.lordpercy.com/archos_pma400_review.htm

ran my benchmark test compiled with GNU C and beat the IBM 3033 results running COBOL. The 3033 won with PL/I and assembler.

http://www-03.ibm.com/ibm/history/exhibits/3033/3033_241902.html

And that is a 1978 machine.

So in SIX YEARS with all of this computing power we can't get a definitive analysis of buildings designed when computers were a joke. This is pathetic. Our engineering schools are accomplices after the fact. I wonder what would happen if the engineering schools were on NISTs back for accurate data. They seem to be sticking thier heads in the sand to me.

I think I saw the first one a few months ago but was turned off by the nuclear stuff at the end. The finite analysis is impressive though. I can't fathom how we can get out of this mess. Consider all of the people that would not want to admit they were wrong after six years of saying the planes did it. A lot of people seem to get angry with me for demanding to know the tons of steel and concrete on every level but these same people will insist they know physics. They keep asking who did it with how much explosives and all I am saying is that the planes couldn't do it.

I am going to have to get back to work on that genetically engineered virus that is fatal to people with IQs below 120. LOL

psik

dMole
05-27-2008, 03:49 AM
Hi psik,

Here's a paper that was recently brought to my attention- Mitigation of Motion.

http://www.911-strike.com/mitigation_of_motion.pdf

It did mention visco-elastic mounts in the WTC Towers- first I've seen that anywhere IIRC.

I agree on the 2 FEA vids that I linked and a "grain of salt," but can you check out all of them for me? Your opinion/review carries more "mass" than some IMHO ;). Just turn down the sound, or crank up the iPod. I really did like his FEA work- it looked more reasonable than Purdue's IMHO. It still looked like a "ridgid" building mount to me though BTW, and I don't agree there at all.

psikeyhackr
05-27-2008, 04:48 PM
I encountered mention of the visco-elastic dampers some time last year.


The real culprit
I have experienced skyscraper sway, being extra-sensitive to it. Sway is handled by visco-elastic dampers. Without them, these buildings would have to be 10 times strongers so that they can stand up to the wind. The WTC towers had thousands of such dampers between the beams and the concrete. In other words, everything was glued together using 3M material and these products from the late 60s were not exactly state-of-the-art - and the WTC was the first use of them due to its sheer walls and wind loads.

The visco-elastic dampers melted under the heat, producing live loads. No one wants to mention them because a lot of skyscrapers would have to be torn down were that the case. Look it up :)
How visco-elastic dampers failed (http://www.designcommunity.com/discussion/7595.html)
http://wakeupfromyourslumber.blogspot.com/2006/09/911-can-you-keep-secret-i-hope-not.html

Although they might have something to do with starting the collapse I can't see them having anything to do with the buildings coming straight down that fast.

Do you have any thoughts about the top of the building remaing centered on the mass it would be crushing below? There would be constant massive and random vibration and I would think if it got just slightly off center it would begin crushing the building below unevenly which would force it more off center so it would inevitably fall off the side. And yet we are supposed to regard it as conceivable that this straight down gravitational collapse happened twice.

Urich has shown me another spreadsheet.

http://www.cool-places.0catch.com/docs/calcCollapse.xls

But when I mentioned that off center business he says there were no lateral forces. I am thinking physics only conforms to math perfectly in a vacuum when the forces don't involve physical contact. When BIG, HEAVY things start rubbing together the complications get really messy.

psik

psikeyhackr
05-27-2008, 09:54 PM
By the way that second video showed 300 tons for the weight of a floor slab including the trusses and pans. I presume he meant an entire floor slab. But I did these calculations for just the concrete some time ago.

206 ft * 206 ft = 42,436
86 ft * 136 ft = 11,696 core
=====
30,740 sq ft * 1/3 ft thick = 10,246.66 cu ft * 100 lb/cu ft / 2000 lb/ton = 512 tons


So I don't know how he got 300 tons total.

psik

dMole
05-28-2008, 12:34 PM
Hi psik,

According to the US Army Corps of Engineers' EC 1110-2-6054, Sec 7.a.1 [p. 4 of 9]:

"1. The density of LDC [low density concrete] typically ranges between 760 and 2,000 kg/m^3 (110 to 125 lb/ft^3) (Holm and Bremner 2000). Compressive strengths of 17 MPa (2,460 psi) or higher are easily attained...

2. Although density levels are conspicuous throughout the discussion of LDC, there is no standard specification for this property. Specification requirements on density are developed on a project-specific basis."

http://www.usace.army.mil/publications/eng-circulars/ec1110-2-6054/entire.pdf

This should give a higher load/floor than you got by 10-25%. The 300 tons looks way light though.

I recently found a new toy for you if you are interested. It is a pretty big free download though for non-commercial use. You can get velocities, and graph data from video, after setting up the scale. Take a look:

http://physicstoolkit.com/

http://physicstoolkit.com/ptk60.zip

Here's a video that is a portion of what Richard Gage will be using in his new DVD that was produced with Physics Toolkit:

http://www.youtube.com/watch?v=POUSJm--tgw

Enjoy.

psikeyhackr
05-28-2008, 11:56 PM
About that 300 ton floor again.

That video only showed one truss length. The real building had two truss lengths, 30 ft and 60 ft I think. So maybe his model had a square core with only one truss length and that accounts for the lower weight. He talked about sinplifying.

psik

psikeyhackr
09-08-2008, 02:17 PM
I recently but somewhat accidentally ran across something interesting in the NCSTAR report.

On the matter of mass distribution of the towers the NIST says this:


2.4.3 Single Impulse Excitations

Accurate estimation of the tower’s motion during the airplane impact required detailed knowledge of the geometry, weight distribution, and impact velocity of the aircraft, as well as detailed knowledge of the geometry, weight distribution, and structural strength of the tower. At the time of this test series (fall 2003), much of this information was unknown, and the impact motion could only be roughly estimated. To allow this estimate to be made quickly, many simplifying assumptions were made regarding the nature of the impact.
http://wtc.nist.gov/NISTNCSTAR1-5D.pdf page 74


Since people don't just accidentally decide how much steel and concrete to put on every level of a 1360 foot building that can withstand 100 mph winds the above statement is not surprising. The peculiar thing is that this was not discussed A LOT in preparing to analyze the event back in 2001.

I don't understand why they couldn't have had that info on the building by fall 2003 though and I certainly don't understand why we don't have it now. WTF

I love the jargon they have to come with for these kind of reports, " Single Impulse Excitations". You have to stop and think, "What the hell does that mean?" Oh. it was hit real hard one time and started vibrating. DUH! 500 mph airliners do that, but only once.

The south tower moved 12 inches at the 70th floor which was 130 feet below the impact at the 81st floor. The tower oscillated for FOUR MINUTES.

http://stj911.org/jones/docs/Jones_ma3deb0b.jpg WIDTH=585 HEIGHT=359


These are physical data, showing a characteristic nearly exponential decay (damping) of the oscillation. Observed oscillation of the WTC 2 Tower provides compelling empirical evidence that it was hit by a fast-moving jetliner. Any claim to the contrary must confront these published data or the analysis thereof.
http://wtc.nist.gov/NISTNCSTAR1-5.pdf p. 26 It will not do in scientific inquiry to ignore data like this – even if one does not trust the source for some reason. In other words, the argument must be to the DATA, not to the source (ad hominem).
http://stj911.org/jones/Jones_Replyto_Reynolds_Wood.html

So that Single Pulse Excitation was caused by a lot of kinetic energy from the plane and the amount of energy which produced structural damage cannot be computed from the total energy of the aircraft without calculating how much produced this behavior in the building and that requires reasonably accurate distribution of steel and concrete information. And where does the NIST show that data and do those calculation?

psik

psikeyhackr
09-08-2008, 09:36 PM
http://wtc.nist.gov/NISTNCSTAR1-5.pdf p. 26

That page 26 is PDF page 80. The graph of the oscillation is at the bottom.

psik

psikeyhackr
10-07-2008, 09:14 AM
In my rarely humble opinion (LOL) many of the people who claim the WTC towers underwent gravitational collapse seem to exaggerate what gravity can do. This is a table showing the velocity and distance fallen by an object from a stationary start. In the first 1/10th of a second the mass moves less than 2 inches and is only traveling at 3.2 ft/sec. So a gravitational collapse of the WTC meant the falling top portion must have accelerated what it struck much more than gravity could have and also have broken whatever was supporting that intact portion of the building.


v == initial velocity
Time V = at + v D = 1/2 at^2 + vt
v = 0
00.1 3.2 ft/sec 0.16 ft 1.92 in.
00.2 6.4 ft/sec 0.64 ft 7.68 in.
00.3 9.6 ft/sec 1.44 ft 17.28 1n.
00.4 12.8 ft/sec 2.56 ft
00.5 16.0 ft/sec 4.00 ft
00.6 19.2 ft/sec 5.76 ft
00.7 22.4 ft/sec 7.84 ft
00.8 25.6 ft/sec 10.24 ft
00.9 28.8 ft/sec 12.96 ft
01.0 32.0 ft/sec 16.00 ft
01.1 35.2 ft/sec 19.36 ft
01.2 38.4 ft/sec 23.04 ft
01.3 41.6 ft/sec 27.04 ft
01.4 44.8 ft/sec 31.36 ft
01.5 48.0 ft/sec 36.00 ft
01.6 51.2 ft/sec 40.96 ft
01.7 54.4 ft/sec 46.24 ft
01.8 57.6 ft/sec 51.84 ft
01.9 60.8 ft/sec 57.76 ft
02.0 64.0 ft/sec 64.00 ft

No matter what brought the towers down the conservation of momentum cannot have been violated. This is the equation for an inelastic collision in which two masses stick together. If the second mass is stationary then v2 is zero.

Conservation of Momentum:

(m1 * v1) + (m2 * v2) = (m1 + m2) * v3

This means the ratio of the stationary mass to the impact mass greatly affects the resulting velocity. If the impact mass is smaller then it will be slowed considerably, but in the opposite case the velocity of the stationary mass will change a lot. But in a gravitational collapse there will be the additional effect of gravitational acceleration before and after impact.

So I have done the calculations for 3 "magical" cases. In each case four masses are magically suspended and when struck from above each mass is released with no resistance. In case #1 the 4 masses are are equal, 2.5 tons each. In case #2 the masses are in the sequence 1, 2, 3 and 4 tons from top to bottom. Case #3 is the reverse sequence of 4, 3, 2 and 1 ton. When the masses are struck from above they begin moving on the basis of conservation of momentum and undergo gravitational acceleration until the next object is struck. Case #0 is just a 10 ton mass dropped from 64 feet with no impacts and is used as a reference case.



mass 1 mass 2 mass 3 mass 4
64 feet feet 48 feet 32 feet 16

Case 0 10 ton 0 0 0
speed 0 32 45.25 55.43 64 ft/sec
time 0 1 1.41 1.73 2 sec

Case 1 2.5 ton 2.5 2.5 2.5
speed 0 32 16 35.78 23.85 39.91 29.93 43.82 ft/sec
time 0 1 1.618 14% 2.12 23% 2.554 sec 28%

Case 2 1 ton 2 3 4
speed 0 32 10.67 33.74 16.87 36.17 21.70 38.66 ft/sec
time 0 1 1.721 22% 2.324 34% 2.854 sec 43%

Case 3 4 ton 3 2 1
speed 0 32 18.29 37.35 29.05 43.23 38.91 50.37 ft/sec
time 0 1 1.58 12% 2.023 17% 2.381 sec 19%



The Case line specifies the weight of mass at each of the 4 heights, 64, 48, 32 and 16 feet. These heights were chosen because they correspond to the "1/2 * 32 feet/sec^2" that is in the distance from acceleration equation thereby making calculations easier.

The speed line has the velocity of the net mass before and after impact based on conservation of momentum.

The time line has the time for the mass to fall to that point and the percentage difference from Case 0.

A body in freefall dropped from the top of the World Trade Center would have taken 9.2 seconds to reach the ground. The NIST says the tower that took longer to collapse did it in 11 seconds. So that is only 20% longer than the freefall time. But the WTC collapses required that the tens of thousands of tons of steel and concrete which had held up the buildings for 28 years be bent and broken and crushed. So how is it that only my absurd and miraculous collapse with inverted masses and disappearing supports comes down that fast in relation to freefall? A skyscraper must be bottom heavy and Case #2 using that distribution has double that percentage of time but it didn't require kinetic energy be used to break supports.

So what is the story with all of these people that claim there was a gravitational collapse but also pretend that knowing the TONS of STEEL and TONS of CONCRETE on every level isn't necessary? I have demonstrated that changing the distribution of mass alters the collapse time regardless of the strength of the material involved and how much kinetic energy would be required to break it.

Time and velocity calculations after impacts:


After Impact #1:
Case 1: 16 = 16t^2 + 16t 1 = t^2 + t t = 0.618 19.78+16
Case 2: 16 = 16t^2 + 10.67t 1 = t^2 + 0.666875t t = 0.721 23.07+10.67
Case 3: 16 = 16t^2 + 18.29t 1 = t^2 + 1.143125t t = 0.58 18.56+18.79

After Impact #2:
Case 1: 16 = 16t^2 + 23.85t 1 = t^2 + 1.490625t t = 0.502 16.06+23.85
Case 2: 16 = 16t^2 + 16.87t 1 = t^2 + 1.054375t t = 0.603 19.30+16.87
Case 3: 16 = 16t^2 + 29.05t 1 = t^2 + 1.815625t t = 0.443 14.18+29.05

After Impact #3:
Case 1: 16 = 16t^2 + 29.93t 1 = t^2 + 1.870781t t = 0.434 13.89+29.93
Case 2: 16 = 16t^2 + 21.70t 1 = t^2 + 1.35625t t = 0.53 16.96+21.70
Case 3: 16 = 16t^2 + 38.91t 1 = t^2 + 2.431875t t = 0.358 11.46+38.91

psik

psikeyhackr
03-02-2009, 04:16 PM
I have uploaded a 1 minute segment of a collapse demo.

http://www.youtube.com/watch?v=HYG9cdgwyqI

It is just washers held by chopped down toothpicks stuck in holes drilled at 1 inch intervals. There will be a lot more drops in the completed video. My falling mass is a stack of 20 washers that weighs 3.8 oz. But in order to fall it has to break off the tooth picks. I show in another segment that a toothpick can hold 20 and 40 and 60 washers. I didn't tape it but I explain that the stack of 20 breaks a toothpick 33% of the time when dropped from 1 inch and 100% of the time when dropped from 2 inches. I drop it from 12 inches in all of the videos.

So with no washers on the toothpicks an average of 17.7 are broken in 3 trials. With various masses it stops after breaking from 6 to 8. So the effect of conservation of momentum on the mass combined with the energy required to break the toothpicks brings the mass to a stop every time in less than half that of toothpicks alone.

psik

psikeyhackr
03-21-2009, 07:09 AM
Finally!

http://www.youtube.com/watch?v=LXAerZUw4Wc

psik