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NOVA Remake of "Why the Towers Fell" 9-5-06

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petgoat Donating Member (1000+ posts) Send PM | Profile | Ignore Sun Jul-23-06 08:03 PM
Original message
NOVA Remake of "Why the Towers Fell" 9-5-06
To be entitled: Building on Ground Zero

Website up 8-22-06

http://www.pbs.org/wgbh/nova/wtc/

They've taken down this extremely dishonest page:

http://911research.wtc7.net/disinfo/experts/articles/eagar_nova/nova_eagar1.html

Hope they hire Jim Hoffman as a consultant.
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Carefulplease Donating Member (749 posts) Send PM | Profile | Ignore Sun Jul-23-06 09:10 PM
Response to Original message
1. There is nothing dishonest in the original page.
The commentator complains about the core columns not being
seen in one very schematic picture. But they are clearly mentioned
in the caption of that pucture, and they are even depicted in
the very next picture.

As for the commentator's other complains they are mostly
naïve rants of somebody ignorant of the laws of physics
and of elementary principles of structural engineering.

The theory presented in the original page is fine and fully
consistent with the knowledge available when that page was
created.



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petgoat Donating Member (1000+ posts) Send PM | Profile | Ignore Mon Jul-24-06 01:32 AM
Response to Reply #1
2. The original page is very dishonest.
Edited on Mon Jul-24-06 01:33 AM by petgoat
Two out of three of the WTC graphics are quite misleading. The animation eliminates the
transverse trusses that would have made the unzipping pictured impossible. The other
shows gratuitous non-structural core slabs floating in air--a magical house of cards.

Dr. Eagar's theory is silly, and obviously was concocted without reference to the blueprints.
It requires that the perimeter clips be so flimsy the floors unzip from the walls, but the
core clips are so strong that the collapsing floors tear down the core.

Dr. Eagar's assertion that the building is too big to fall anywhere but down is also silly.
I guess he'll tell us next that the Michelangelo was too big to turn around, so it would
have to steam forward from Italy to NY, and then backward from NY to Italy.



You seem not to appreciate the major differences between the NOVA/Eagar/FEMA zipper theory
and the NIST theory. The former assumes that the floors break free from the columns,
leaving them unsupported laterally so that they buckle outward. The latter assumes that
the floors hold so tenaciously to the columns that the columns buckle inward--despite the
bracing effect of the adjacent floors.

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petgoat Donating Member (1000+ posts) Send PM | Profile | Ignore Tue Jul-25-06 10:50 AM
Response to Reply #2
4. Also, according to Kevin Ryan, NIST's floor-sag studies
achieved only a few inches of sag despite the application of
fudge factors to ensure the desired results, but NIST's computer
models used a sag of over 40 inches to impose the desired buckling
stresses.

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Carefulplease Donating Member (749 posts) Send PM | Profile | Ignore Tue Jul-25-06 11:35 PM
Response to Reply #4
12. Ryan badly misrepresents the study's purpose and results.
Ryan took no part in this research that was performed for NIST by another division of Underwriter than the one he used to work with. His own field was water sanitation, I think. These studies were performed to validate the fire ratings of the floor trusses and *not* to establish how much full floor assemblies would have sagged in the actual situation and context (aircraft damage, etc.) of the WTC towers. They were performed with undamaged trusses (the long span trusses were 1/2 scale models) that also had undamaged fireproofing foam. Fire exposure pretty much utterly destroyed them after 2-3 hours. The essays were interrupted just short of actual collapse in order to spare the expensive test furnace and measure instrumentation.




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petgoat Donating Member (1000+ posts) Send PM | Profile | Ignore Wed Jul-26-06 12:01 AM
Response to Reply #12
14. Right, they used too much heat, and they heated them too
Edited on Wed Jul-26-06 12:13 AM by petgoat
long, and they still couldn't get them to sag more than a few inches.

And then they inserted a value of over forty inches sag into their computer
model.

Kevin Ryan didn't need to participate in the studies to know bad science when
he sees it.
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Carefulplease Donating Member (749 posts) Send PM | Profile | Ignore Wed Jul-26-06 12:47 AM
Response to Reply #14
16. They had undamaged insulation...
They had undamaged insulation. They had not been damaged by a plane. They were scaled down. They were not integrated in a global model (no variations on the vertical load of perimeter columns.) They were not allowed to sag anymore when collapse was deemed imminent. This was *not* a test of a global collapse scenario at all. It was a test of the fire rating of *intact* floor elements. Ryan, who had nothing to do with this research, and no relevant qualification, is confused.

NIST did not "plug" a value for the sagging in the model. NIST, however, did "plug" carefully measured empirical values of the inward buckling of perimeter walls. The actual use of empirical data to tune up highly complex finite element simulations is something that, for some reason, baffles people like Jones, Wood and Ryan.
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mhatrw Donating Member (1000+ posts) Send PM | Profile | Ignore Wed Jul-26-06 01:17 AM
Response to Reply #16
18. Why did "they" have undamaged insulation?
And what hard scientific evidence can you present to the effect that the WTC towers' insulation was badly damaged?

What scientific basis do you have for believing that variations on the vertical load of perimeter columns would lead to significantly different results?

Most significantly, how long did these tests run compared to the amount of time the WTC towers were exposed to fire before they collapsed?

What baffles critics about NIST's "scientific" analysis is why they forewent examining the physical evidence in favor of using computer models that were specifically reverse-engineered with whichever input parameters were necessary to initiate structural failure.

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Carefulplease Donating Member (749 posts) Send PM | Profile | Ignore Fri Jul-28-06 06:52 PM
Response to Reply #18
26. Don't you know where to find the evidence?

And what hard scientific evidence can you present to the effect that the WTC towers' insulation was badly damaged?


NIST tested the resistance of the material to impact and estimated the distribution of impact debris.

http://wtc.nist.gov/NISTNCSTAR1-5D.pdf
http://wtc.nist.gov/NISTNCSTAR1-6A.pdf
http://wtc.nist.gov/NISTNCSTAR1-6C.pdf

What scientific basis do you have for believing that variations on the vertical load of perimeter columns would lead to significantly different results?


The columns normally resist bowing. When they do bow, for whatever reason (heat, pull-in forces), then increased load further facilitates bowing. When the load limit is reached then bowing is sustained with zero contribution from lateral pull forces. Above that point the floor system work in compression. This was not tested in the fire rating experiment. That was not the purpose of the experiment! Only normal conditions were assumed where the floor were neither fully restrained nor unrestrained but something in between. This is all documented in the NIST report.


Most significantly, how long did these tests run compared to the amount of time the WTC towers were exposed to fire before they collapsed?


Two or three times as long -- until the trusses were close to collapse. The fire time-temperature curve was standardized so that wasn't the condition in the towers either. Read the report to see the chronicle of the truss models progressive noisy destruction.

http://wtc.nist.gov/NISTNCSTAR1-6B.pdf

Why shouldn't these undamaged floor elements have lasted longer than did those in the towers? Do you believe the fireproofing effect to be merely decorative? Wouldn't the structural impact damage from the aircrafts have any effect?

What baffles critics about NIST's "scientific" analysis is why they forewent examining the physical evidence in favor of using computer models that were specifically reverse-engineered with whichever input parameters were necessary to initiate structural failure.


They adjusted parameter values that were unknown within a reasonable range (combustible loading and severity of internal damage) so as to best track the evolution of measurable parameters in model runs. In those model runs that best matched the observed fire progression, smoke output, perimeter column bowing, etc., collapse ensued in the model. When some other values were input, the towers stood, but the evolution of the model long before collapse initiation did not match observed parameters either. So there was an independent empirical basis for discarding these parameter values.
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petgoat Donating Member (1000+ posts) Send PM | Profile | Ignore Wed Jul-26-06 10:16 AM
Response to Reply #16
20. Empirical measurements?
Edited on Wed Jul-26-06 10:18 AM by petgoat
It's not surprising that you believe NIST has empirical measurements, because they
work very hard to make that impression.

The chart below is a metaphor for the dishonesty of the NIST report: its chaotic
specificity makes it look like they placed thermocouples on an 8" grid, but in fact
it's just their wish-list of the temperatures they need to explain the collapse.
(mhatrw's characterization of the report as "reverse engineered" is spot on!)






The empirical evaluations I trust are those of FDNY Chief Orio Palmer, who radioed
from the 78th floor that he was going to "knock down" a couple of "isolated" fires,
and Brian Clark, who walked down from 86 through the fire zone, saw only a few
flames, and stopped at the 31st floor to make phone calls before opining that "no
way" could the towers fall.

Please advise as to who made the empirical observations of the perimeter buckling.
Were any of these buckled perimeter columns collected? They should have been
conspicuously burned. How did NIST's photo analysis allow for the possibility that
their photos were distorted by laminar sheets of hot air rising along the sides of
the building, as shown in these photos?





What was the purpose of testing the fire rating of the floor trusses if not to
measure the sag and confirm their postulated failure mechanism? Is there any
evidence that any region of any floor was actually burned for two hours?

Will you share with us your source for your analysis of the NIST report?

How is the fact that Kevin Ryan did not participate in the NIST studies relevant?
IMHO haviong participated in such a sham disqualifies one from any claim to
objectivity, unless one wants to play the role of whistleblower.


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Carefulplease Donating Member (749 posts) Send PM | Profile | Ignore Sat Jul-29-06 03:22 AM
Response to Reply #20
32. Why can't you read the text...
Petgoat wrote:

"The chart below is a metaphor for the dishonesty of the NIST report: its chaotic
specificity makes it look like they placed thermocouples on an 8" grid, but in fact
it's just their wish-list of the temperatures they need to explain the collapse."


Is that how you assess a report? You pull out a random picture and make wild guesses as to its significance?

Sorry, it does not "look like they placed thermocouples on a grid" at all. The report title, the summary and the text make it perfectly clear that this represents the result of a reconstruction using a fire dynamics simulator. The perimeter data represents recorded empirical evidence (photographs and videos) against which the simulation runs are assessed.


See p.69 of this report for a description of the simulator that produced the data displayed on such pictures.

http://wtc.nist.gov/NISTNCSTAR1-5.pdf

Refer to the whole report to learn about the visual evidence used by NIST, the combustible distribution assessment and full details of the fire and heat transfer modeling.

Read this about Palmer's observations:

http://www.jod911.com/evidence.pdf

I do not have "sources" for my interpretation of the NIST reports. Neither should you have to rely on any. Go with the executive summaries when you do not want to get bugged down with details. Proceed to the roll-up main reports and detailed sub-reports when you want to dig deeper on specific issues. Do not trust Kevin Ryan to perform your own investigations. He is quite inept at this game.
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petgoat Donating Member (1000+ posts) Send PM | Profile | Ignore Sat Jul-29-06 03:46 AM
Response to Reply #32
33. I should not rely on "sources" for criticism of NIST, but
I should let you tell me that Kevin Ryan is inept (an opinion for which you provide
no examples or authority).
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Carefulplease Donating Member (749 posts) Send PM | Profile | Ignore Sat Jul-29-06 10:34 AM
Response to Reply #33
34. Haven't you noticed any contradictions yet...
Haven't you noticed any contradictions yet between Ryan's claims about the NIST report and what is actually found in the NIST report? I pointed out many of these already. Ryan isn't an "insider". His own main source *is* the public NIST report. He only seems capable of twisting, bending and misrepresenting the NIST claims.
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petgoat Donating Member (1000+ posts) Send PM | Profile | Ignore Sat Jul-29-06 12:24 PM
Response to Reply #34
36. Maybe if you would specify some contradictions, I would
Edited on Sat Jul-29-06 12:26 PM by petgoat
look into them, but your present argument is the equivalent of waving a
Big Fat Book and claiming "it's all in here!" I don't have time to read
the NIST report right now.

That NIST did not issues a very strong statement to the effect of
"How do they expect us to conduct an investigation when they destroyed
the steel?" is proof of the basic dishonesty and scientific invalidity
of the report.

The caption of this picture is a damned lie. The report is a damned lie.




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Carefulplease Donating Member (749 posts) Send PM | Profile | Ignore Sat Jul-29-06 02:05 PM
Response to Reply #36
37. Fine, don't read it. And stop making ungrounded claims about it.
Your extracted that picture from chapter 6 of this document:

http://wtc.nist.gov/NISTNCSTAR1CollapseofTowers.pdf

The title of the chapter is: "Reconstruction of the Collapses"

Notice the word "reconstruction".

The sections of this chapter are:

6.10.1 The Need for Simulation
6.10.2 Modeling Approach
6.10.3 The four cases
6.10.4 Characterization of the fires

The picture comes from the fourth section:

"For each of the four scenarios, FDS (Fire Dynamics Simulator) was used to generate gas temperatures and radiation environments on each of the floors. The results of the perimeter fire were compared with the fire duration and spread rate as seen in the photographs and videos. (...) An example is shown in figure 6-36"

Notice the words "scenarios", "generate", "example" and "perimeter". You do not have to dig very deeply. This in on the same page your picture comes from -- it's right above the picture!

I see no lie in this section of the report. I only see carelessness in your characterization of data you needlessly extract from the proper context.


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dailykoff Donating Member (1000+ posts) Send PM | Profile | Ignore Sat Jul-29-06 10:31 PM
Response to Reply #37
41. I've read it and he's right. It's like a moldy sack of potatoes:
there are bugs in every bite.
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Jazz2006 Donating Member (1000+ posts) Send PM | Profile | Ignore Mon Jul-31-06 01:31 AM
Response to Reply #37
45. CarefulPlease...
this is the usual tactic of a certain group of CTers here... goat, dailykoff, the poster identifying him/her self as the fictional miranda priestly, and a couple of others ... when they cannot respond meaningfully to your post, one of them will take one little piece of it and pretend to "respond" to your post in an effort to deflect the discussion to a peripheral point, then another will jump in with a one liner purporting to support the 'new' discussion point that the first one has deflected to, albeit with no basis in fact whatsoever, and often another one or two will chime in with "rah rah" posts such as "gee, I never thought of that before" or "wow, I never saw it that way before" or "good find" even though the exact same things that they pretend are new to them have been posted in these very forums dozens, scores, if not hundreds of times before and to which they have responded the exact way dozens, scores, if not hundreds of times before.

It's a strange old world in conspiracy land.

But this kind of behaviour on their part is just par for the course.

CTers love it when there's a MSM reference to the tinhat theories that they espouse, (even though they claim to hate the MSM the rest of the time) because it means that several more gullible people will temporarily buy into the tinhat theories before and unless the newly initiated actually examine the facts and evidence and realize how ridiculous most of the CT theories are.

But that's just par for the course. The vast majority of those who initially buy into the conspiracy theories change their minds when they actually look at the facts and evidence. There will always be, however, a certain tiny minority for whom facts and evidence mean nothing and they will never, ever be convinced of anything beyond their own misguided, illogical, unsupported "beliefs", facts and evidence be damned - and the CT sites that they cite over and over again will sell more dvds ~ woo hoo.

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mhatrw Donating Member (1000+ posts) Send PM | Profile | Ignore Wed Jul-26-06 01:05 AM
Response to Reply #12
17. You badly misrepresent the study's results.
Why?

Do you really think this study offered support for NIST's WTC collapse theories? If so, please explain how.
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Carefulplease Donating Member (749 posts) Send PM | Profile | Ignore Sat Jul-29-06 03:17 PM
Response to Reply #17
39. That was not their role but they did...
The purpose of the study was to establish the fire ratings of the floor trusses. It however confirmed that the trusses could be destroyed by fire and that the heated floors should be expected to sag.

This was demonstrated in the case of floors (some of them 1/2 scale models) that had intact fireproofing (SFRM) and that had not been damaged by an aircraft impact and that did not suffer injury from surrounding failing structures.
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vincent_vega_lives Donating Member (1000+ posts) Send PM | Profile | Ignore Tue Jul-25-06 11:08 AM
Response to Reply #2
5. You know better than Dr Edgar?
I can't comment on the truss system as I am not familier with your assertions. Somehow I suspect you got that info from another CT website.

This analogy is laughable, and just shows you really have no clue what Dr Edgar is refering to:

Dr. Eagar's assertion that the building is too big to fall anywhere but down is also silly. I guess he'll tell us next that the Michelangelo was too big to turn around, so it would have to steam forward from Italy to NY, and then backward from NY to Italy.

You REALLY don't understand structual dynamics.
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petgoat Donating Member (1000+ posts) Send PM | Profile | Ignore Tue Jul-25-06 05:07 PM
Response to Reply #5
6. I understand a lot about structural dynamics.
Edited on Tue Jul-25-06 05:10 PM by petgoat
When I was four years old I took four sticks and a piece of plank and four nails and
I built a stool. Then I sat on it and it went sideways and I fell on my ass.

Dr. Eagar has been very silent of late. It appears that nobody will defend his silly
pancake theory that was conventional wisdom for three years. It looks like NOVA
purged him from their website. If the truss mounts were so weak that they unzipped,
how then did the floors tear down the core? You can't have it both ways.

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hack89 Donating Member (1000+ posts) Send PM | Profile | Ignore Tue Jul-25-06 05:36 PM
Response to Reply #6
7. Did you build a stool with ...
tens of thousands of stick? If all those joints failed, would you expect to fall sideways?
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petgoat Donating Member (1000+ posts) Send PM | Profile | Ignore Tue Jul-25-06 06:16 PM
Response to Reply #7
8. If 20,000 joints failed simultaneously
I would expect it to fall straight down into its footprint at freefall speed.

If a few joints failed in an assymetrical pattern, I would expect an asymmetrical
collapse. Stand on a five foot step ladder. Have someone saw one of the legs
through. Does it collapse straight down?
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hack89 Donating Member (1000+ posts) Send PM | Profile | Ignore Tue Jul-25-06 06:28 PM
Response to Reply #8
9. Poor analogy
too simple a structure with only two supports.

a better one would be a house made of match sticks. If I removed some side supports it would lean. If I removed some supports while I sat on it, it would collapse straight down.

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dailykoff Donating Member (1000+ posts) Send PM | Profile | Ignore Tue Jul-25-06 07:22 PM
Response to Reply #9
10. A house made of match sticks, right.
That would be next to the gingerbread castle in Fantasyland.

:crazy:
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hack89 Donating Member (1000+ posts) Send PM | Profile | Ignore Tue Jul-25-06 07:59 PM
Response to Reply #10
11. Comprehension is not your strong suit, is it?
it was a reference to the complexity of the structure. He was comparing the WTC to a ladder with two supports. He also neglected to place a massive weight on top of that ladder.

Do you believe that the WTC would fall like a 5 foot ladder with one leg missing? Now that would belong in fantasyland.
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petgoat Donating Member (1000+ posts) Send PM | Profile | Ignore Tue Jul-25-06 11:58 PM
Response to Reply #11
13. Your house of match sticks is also a poor
model.

Your dead weight sitting on it doesn't match the building.

The damaged perimeter columns were not an issue because the weight above was transferred to
the core columns by the hat truss, which was pulled down by the perimeter columns on the other
side.



The only way this is going to fail is if the core columns on the damaged side fail, and then
the perimeter columns on the other side (which are in tension)have to fail too.

Kevin Ryan said that the perimeter columns were designed for a 2000% live load and that the
live load and the dead loads were about equal. And steel is much stronger in tension than
in compression.

IF this thing fails, you're going to get buckling in the core on one side, then the perimeter
columns on the other side have to are going to pull apart, and the top is going to tilt (as
we saw in the south tower).

Asymmetrical failure inevitably leads to lateral vectors, but frankly I'm having a hard time
imagining how it fails.






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AZCat Donating Member (1000+ posts) Send PM | Profile | Ignore Wed Jul-26-06 09:18 PM
Response to Reply #13
22. Steel is not stronger in tension than compression.
A given structural member might be, but steel itself isn't. Concrete, on the other hand, can handle much greater compressive loads than tensile loads.

Where does the 2000% number come from?
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Carefulplease Donating Member (749 posts) Send PM | Profile | Ignore Wed Jul-26-06 12:29 AM
Response to Reply #2
15. The images are missleading...
...if you take them too seriously as anything more than rough illustrations of specific concepts and if you fail to read the accompanying text. People do not believe that because not all
pictures show the columns that therefore they do not exist.

Dr. Eagar's assertion that the building is too big to fall anywhere but down is also silly.
I guess he'll tell us next that the Michelangelo was too big to turn around, so it would
have to steam forward from Italy to NY, and then backward from NY to Italy.


There is no structural element in the WTC towers that could
survive to perform the function of a hinge around which
the top portion of the tower could rotate ("tip over").
Gravity pulls downwards and if the top portion were to
rotate around some horizontal axis, then its center of
mass would acquire some massive horizontal momentum.
The horizontal reaction forces on the columns that are
part of the pivot (even assuming -- per impossibile --
that they could survive the bending and take up all the
vertical load of the top section) would subject them to
a lateral stress orders of magnitude greater than what
they are designed to withstand. This is not the wooden
stool you built in your youth. Think scale.

You seem not to appreciate the major differences between the NOVA/Eagar/FEMA zipper theory
and the NIST theory. The former assumes that the floors break free from the columns,
leaving them unsupported laterally so that they buckle outward. The latter assumes that
the floors hold so tenaciously to the columns that the columns buckle inward--despite the
bracing effect of the adjacent floors.


There is nothing contradictory in saying that trusses
connections are strong enough to pull columns inward,
but only so much. Also, some trusses work together and
others, less so. They bear individually more load. The
planes did some damage already, you know.

Eagar's and the NIST's scenarios are different but the
latter is based on more detailed evidence. The former
describes a way the towers *could* have collapsed if
the conditions had been slightly different.



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mhatrw Donating Member (1000+ posts) Send PM | Profile | Ignore Wed Jul-26-06 01:35 AM
Response to Reply #15
19. What a bunch of nonsense.
Edited on Wed Jul-26-06 01:35 AM by mhatrw
There is no structural element in the WTC towers that could survive to perform the function of a hinge around which the top portion of the tower could rotate ("tip over").

What?

Gravity pulls downwards

Yes

and if the top portion were to rotate around some horizontal axis, then its center of mass would acquire some massive horizontal momentum.

Not necessarily and not necessarily definitive.

The horizontal reaction forces on the columns that are part of the pivot (even assuming -- per impossibile --that they could survive the bending and take up all the vertical load of the top section) would subject them to a lateral stress orders of magnitude greater than what they are designed to withstand. This is not the wooden stool you built in your youth. Think scale.

Is it actually your contention that if someone blew out the northmost 1/2 and the southmost 1/8 of a WTC tower from floors 35-65 that the top of the building wouldn't topple over to the north? Seriously? If so, please elucidate further.
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Carefulplease Donating Member (749 posts) Send PM | Profile | Ignore Fri Jul-28-06 04:51 PM
Response to Reply #19
23. There is no way the top could topple over.
When the top starts rotating as a result of asymmetrical failures, then global collapse must almost immediately ensue. Suppose it does not, then all the columns on one side of the rotation axis are compressed while (almost) all the other columns are being elongated. They all must fail after they reach their compressive or tensile strength limits. The columns that are near the pivot point are bent and subjected to the lateral reaction force F = ma, where "m" is the mass of the upper block and "a" is the horizontal component of the acceleration its center of gravity (gravity only contributes horizontal forces.)

So you have only a handful of columns supporting the middle of the structure, that have not yet been crushed or pulled apart yet, and these are bent and subjected to some huge lateral shear stress. How can global collapse be further delayed? How can the full upper block "topple" over these few compromised columns remnants? (Petgoat's wooden-stool analogy -- trapezoid deformation of a rectangular grid structures -- can not apply here because of the dense spandrel (+hat truss) bracing of most columns. The upper block must rotate rigidly.
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petgoat Donating Member (1000+ posts) Send PM | Profile | Ignore Wed Jul-26-06 12:16 PM
Response to Reply #15
21. The images are dishonest because they are presented as if
they have an engineer's authority.

http://911research.wtc7.net/disinfo/experts/articles/eagar_nova/nova_eagar1.html

The first one illustrates the specific concept all right--by eliminating the structural
elements that interfere with the concept's execution.

The second one illustrates no concept at all, except to contrast the comforting
post-and-beam matrix of conventional construction with the bizarre and pointless picture
of a core built of cards suspended by magic in air. The concept they purport to illustrate--
the massive and extensively cross-braced core built to take all the gravity loads with
a substantial safety factor and redundant design--is strikingly absent from that illustration.

There is no structural element in the WTC towers that could
survive to perform the function of a hinge around which
the top portion of the tower could rotate ("tip over").


So this never happened?





There is nothing contradictory in saying that trusses
connections are strong enough to pull columns inward,
but only so much.


Huh? Eagar claims that the truss clips failed under the insult of
the gravitational load they were designed to resist. NIST claims they
were supernaturally resistant to a lateral force they were NOT designed
to resist.

Also, some trusses work together and others, less so. They bear
individually more load. The planes did some damage already, you know.


That some trusses bear more load than others is all the more reason the
clips should have popped, not buckled the perimeter columns. Every
piece of steel had a stamped ID number. The buckled perimeter columns
could have been pulled out of the pile. Too bad they weren't.

Sorry, but when the Medical Examiner loses Grannie's head (oops! Well,
government is incompetent, don't you know!) I'll remain forever
suspicious of the nursing home's story of how she died. And that doesn't
make me a conspiracy theorist. That just makes me a reasonable concerned
party.






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Carefulplease Donating Member (749 posts) Send PM | Profile | Ignore Fri Jul-28-06 05:34 PM
Response to Reply #21
24. This image does not illustrate a hinge...
If you look at the video, you'll see that the top block has already fallen down 10 floors or so. There is no hinge because there are no columns still connecting the upper and lower sections of the tower. If the top still rotates that is just because of the conservation of angular momentum. This angular momentum was acquired during the phase of collapse initiation, when all columns did not fail simultaneously. This is just the asymmetrical collapse Judy Wood claims should have occurred (while implying that it didn't in fact occur).

I still do not get your point regarding the strength of floor truss connections. They only pull in the perimeter walls when three consecutive floors sag according to NIST. They are not "designed" for this but they are certainly strong enough to do so. Why do you think they aren't?

Some connections *did* fail. This is seen on photographs. The floor slabs are seen to hang through the windows. NIST takes that into account in the global model. Damaged floors that pull alone are prone to disconnect. Undamaged floors that pull together are prone to make walls bow.

Bowing isn't buckling. The former is an elastic deformation and requires a force that is roughly proportional to the displacement. The later occurs when the steel is stressed past the elastic range and undergoes plastic deformation. A limited amount of bowing of vertical columns is enough the greatly reduce their load bearing capacities which must thus be transferred elsewhere.

There are pictures of buckled columns on the NIST site. This was not the primary failure mode, however. Bolt failure was more usual, I seem to remember.


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dailykoff Donating Member (1000+ posts) Send PM | Profile | Ignore Fri Jul-28-06 05:58 PM
Response to Reply #24
25. Ouch, more Eagarography.
You do realize that the fantasy you're elucidating has absolutely no relation to reality?

Let's just take the first painful point. If the top was rotating, it didn't need a "hinge"; it was already rotating, even though it was also falling.

It should have kept rotating and falling, all the way to the ground, or more likely, to the roof of one of the surrounding structures, just like a tree.

But it didn't, because it disintegrated before it could. That means it was blown apart, and that's just one reason why the OCT is a laughable insult to human intelligence.
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Carefulplease Donating Member (749 posts) Send PM | Profile | Ignore Fri Jul-28-06 08:07 PM
Response to Reply #25
27. They disappeared in the clouds of dust and smoke.
Which tower are you talking about? The much shorter top section of WTC1 kept rotating. The top of WTC2 rotated both in the East-West direction and the North-South direction. The perimeter wall of the upper block was funneled inside of the perimeter wall of the lower block and this might have helped reduce its rotational speed around the North-South axis. Some videos show the perimeter walls of the lower section being peeled off and huge segments falling outwards. We do not see what happens to the blocks when they disappear into the dust/smoke cloud below. There is no ground for claiming that they completely turn to dust before they hit the ground.

My reference to a hinge was in answer to Petgoat who seems to suggest that the top block should have fallen off the lower portion of the tower without crushing it. It the upper block merely rotates without there being a hinge that communicates to it any more significant lateral momentum after the collapse in under way, then rotation alone will do nothing to move the center of mass of the upper block faster away from the lower portion of the tower.

Enough debris from WTC2 fell to the West and South to utterly destroy the Marriott (WTC3) to the West, the Greek Orthodox Church to the South and heavily damage many more buildings further to the West and South.
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dailykoff Donating Member (1000+ posts) Send PM | Profile | Ignore Fri Jul-28-06 11:42 PM
Response to Reply #27
28. You bet they did.
That's the point.
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Carefulplease Donating Member (749 posts) Send PM | Profile | Ignore Sat Jul-29-06 01:57 AM
Response to Reply #28
29. Ahem... you just said: "It should" ... "but it didn't"
In the post just before (#25) you were still arguing that continued rotation of the upper block and for it to fall "to the roof of a surrounding structure" *should* be the consequence of gravity driven collapse. But you said "it didn't, because it disintegrated before it could. That means it was blown apart."

I pointed out that it *did* continue to rotate and that the expected damage on surrounding buildings from this rotating block (and from the huge outer wall segments it peeled off and pushed away) while it went down *did* occur.

So, it did not "disintegrate before it could" do the damage.

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dailykoff Donating Member (1000+ posts) Send PM | Profile | Ignore Sat Jul-29-06 02:16 AM
Response to Reply #29
30. They should have fallen. They shouldn't have exploded.
Don't you ever get tired of baloney?
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Carefulplease Donating Member (749 posts) Send PM | Profile | Ignore Sat Jul-29-06 02:42 AM
Response to Reply #30
31. When did they explode?
Did they explode *after* they fell out of visibility into the clouds of dust and smoke that was being ejected from the pancaking floors? If they're obscured when they exploded, how do you know they did explode? Why did huge intact perimeter walls sections fall out the way they did if they weren't peeled off by the falling mass of quite unexploded upper floors?
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dailykoff Donating Member (1000+ posts) Send PM | Profile | Ignore Sat Jul-29-06 11:27 AM
Response to Reply #31
35. When they disappeared in the clouds of dust and smoke.
See? You're catching on.
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Carefulplease Donating Member (749 posts) Send PM | Profile | Ignore Sat Jul-29-06 02:14 PM
Response to Reply #35
38. Why are you twisting my words now?
The dust and smoke is being ejected by the pancaking floors. What is your ground for claiming that the top segment was exploded after it was actually hidden from view? Is it only the top of WTC2 that was exploded? In one video, the top of WTC1 is seen rotating and falling almost all the way to the ground.
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dailykoff Donating Member (1000+ posts) Send PM | Profile | Ignore Sat Jul-29-06 10:04 PM
Response to Reply #38
40. Frankly I'm trying to untwist them
and you keep twisting in fresh nonsense. Now you're back to pancaking which is not worthy of another keystroke.

About the top sections, the picture goat posted a few posts back (#21) is WTC2:



If either top had failed to blow up in midair, it would have been highly conspicuous after the "collapses," and probably would have taken out a healthy chunk of the WFC or some other pricy real estate on the way down.
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Carefulplease Donating Member (749 posts) Send PM | Profile | Ignore Sun Jul-30-06 01:17 AM
Response to Reply #40
42. So "they" wanted to restrict the damage. How thoughtful. n/t
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dailykoff Donating Member (1000+ posts) Send PM | Profile | Ignore Sun Jul-30-06 10:32 AM
Response to Reply #42
43. Call it the miracle of 9/11.
Only money losers got demolished and only politically inconvenient people got killed, apart from the usual collateral damage of course.

And no I don't know why Ted Olsen wanted to get rid of his wife.
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Bolo Boffin Donating Member (1000+ posts) Send PM | Profile | Ignore Sun Jul-30-06 10:38 AM
Response to Reply #43
44. I want to frame that quotation of yours, dailykoff!
Only money losers got demolished and only politically inconvenient people got killed, apart from the usual collateral damage of course.


Only politically inconvenient people, plus all those others. The ability of the human mind to insist on its own interpretation, even while in possession of the information that negates said interpretation, is astonishing.
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Jazz2006 Donating Member (1000+ posts) Send PM | Profile | Ignore Mon Jul-31-06 01:38 AM
Response to Reply #44
46. You're right. That is possibly the most disgusting and
utterly clueless post ever.

Jesus.




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greyl Donating Member (1000+ posts) Send PM | Profile | Ignore Mon Jul-31-06 03:27 AM
Response to Reply #46
48. Possibly still bitter from a purge. nt
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greyl Donating Member (1000+ posts) Send PM | Profile | Ignore Mon Jul-31-06 03:26 AM
Response to Reply #43
47. Your post is atrocious, dailykof
Edited on Mon Jul-31-06 03:27 AM by greyl


atrocious
1. Extremely evil or cruel; monstrous.
2. Exceptionally bad; abominable: atrocious decor; atrocious behavior.
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mirandapriestly Donating Member (1000+ posts) Send PM | Profile | Ignore Mon Jul-31-06 03:55 AM
Response to Reply #47
49. Now you're going for the emotional appeal
Edited on Mon Jul-31-06 03:57 AM by mirandapriestly
Funny, in another thread you said something about emotional appeal's being illogical, but now you're doing it. Who else does that? Oh yeah, The Bush administration. Your post is what is atrocious! Trying to "win" arguments with feigned moral indignation.
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greyl Donating Member (1000+ posts) Send PM | Profile | Ignore Mon Jul-31-06 04:07 AM
Response to Reply #49
50. I'm expressing my opinion to one person, not trying to sway a jury.
Why do you constantly try to censor me in the same fashion that the bush administration does with hard science that is contrary to what they want people to believe?

Still waiting for that apology.
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mrgerbik Donating Member (652 posts) Send PM | Profile | Ignore Mon Jul-24-06 02:49 AM
Response to Original message
3. kick n/t
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