Architects, Engineers, and Scientists Analyze Failings of NIST's WTC 7 Final Report!

Originally posted by exponent
Unless you can present a third option, these are your only choices. Do you agree?

NO, You keep forgetting about the FBI and NTSB reports that still ahve not been released.

Originally posted by Griff
reply to post by Newtons.Bit

 

Indeed. I am finding that your values are more correct. I think that the mechanical engineering site that Valhall posted was either for short pieces or not for A36 steel.

Anyway, here's an unbiased site (I think because it's from '87 and from Canada) that shows you were the more correct one for the calculations. Although, they say 40% but I won't split hairs.

Both the yield stress and modulus of elasticity of steel, the two material properties most important in determining load-carrying capacity, decrease considerably with increasing temperatures (Figure 5).12 At a temperature of 593 ° C,these values will have fallen by at least 40% compared to ambient room temperature levels, meaning that the strength of the steel member will be barely sufficient to resist applied loads (assuming normal safety factors).

irc.nrc-cnrc.gc.ca...

BTW, not that I'm calling AISC biased in any way.

Also, I know what you mean about technical writing. My reports still come back 3, 4 times sometimes. I recently bought a book called "Engineering Your Writing Success". So far, it's a pretty good book.

I've looked at a number of sources as well. They show that somewhere before 600C there is a steep drop in Modulus of Elasticity. Even if it is not 0.30 at 600C, it definitely gets to 0.30 somewhere between 600C and 700C.

I also imagine that various different grades of steel would give fairly different results.

[edit on 21-9-2008 by Newtons.Bit]

Originally posted by ULTIMA1
NO, You keep forgetting about the FBI and NTSB reports that still ahve not been released.

Do you think that somehow these reports will state that it was an inside job?

Originally posted by Newtons.Bit
I've looked at a number of sources as well. They show that somewhere before 600C there is a steep drop in Modulus of Elasticity. Even if it is not 0.30 at 600C, it definitely gets to 0.30 somewhere between 600C and 700C.

www.tms.org...

It is known that structural steel begins to soften around 425°C and loses about half of its strength at 650°C.4 This is why steel is stress relieved in this temperature range. But even a 50% loss of strength is still insufficient, by itself, to explain the WTC collapse. It was noted above that the wind load controlled the design allowables. The WTC, on this low-wind day, was likely not stressed more than a third of the design allowable, which is roughly one-fifth of the yield strength of the steel. Even with its strength halved, the steel could still support two to three times the stresses imposed by a 650°C fire.

[edit on 21-9-2008 by ULTIMA1]

Originally posted by ULTIMA1
www.tms.org...

Why is it you feel compelled to post opinions which have been superseded by the NIST report and more in-depth investigation? Even so you have omitted the paragraph proceeding the one you posted, which is quite dishonest of you.

Originally posted by exponent
Why is it you feel compelled to post opinions which have been superseded by the NIST report and more in-depth investigation?

Who says the NIST report is a more in-depth investigation? NIST used models too. Are you saying the engineers from the source i posted are not good engineers?


You just do not want to accept anything that is different from what you believe do you?

Originally posted by ULTIMA1
Who says the NIST report is a more in-depth investigation?

Are you joking?

Are you saying the engineers from the source i posted are not good engineers?

Not at all, the analysis undertaken at the point this article was written was very minimal. They did not have much to go on.

You just do not want to accept anything that is different from what you believe do you?

I don't know where you get this from, I am more than happy to accept when I am wrong.

Originally posted by exponent
Are you joking?

No, show me that the models NIST did were any better then the source i have posted.

Not at all, the analysis undertaken at the point this article was written was very minimal. They did not have much to go on.

You mean just like NIST since they were late on the building 7 investigation and did not have much evindece?

I don't know where you get this from, I am more than happy to accept when I am wrong.

Then why don't you admit it when i prove you wrong?

Originally posted by ULTIMA1
No, show me that the models NIST did were any better then the source i have posted.

What criteria would you accept? NISTs reports are extensive and located building behaviour the report you quoted did not. This alone should indicate they were more rigorous.

To be honest I'm having a hard time believing you're even asking this question, the source you posted was a few pages of mostly speculation based on engineering principles. NISTs modelling occupies several thousand pages in total including physical tests of areas involved in fire and the construction of the WTC.

You mean just like NIST since they were late on the building 7 investigation and did not have much evindece?

We are talking about WTC1 and 2 here, but regardless NISTs investigation into WTC7 is the most extensive and detailed report yet produced. Your criticism is entirely invalid.

Then why don't you admit it when i prove you wrong?

Because this is simply your own opinion, if you really believe you prove me wrong, challenge me to a moderated debate.

Originally posted by exponent
This alone should indicate they were more rigorous.

But not as rigorous at the FEMA report.

We are talking about WTC1 and 2 here, but regardless NISTs investigation into WTC7 is the most extensive and detailed report yet produced.

NO, it is not more extensive or detailed then the FEMA report.

Originally posted by ULTIMA1
But not as rigorous at the FEMA report.

MUCH more rigorous. Read the damn reports, FEMAs report was quite speculative and an early look into potential failure mechanisms. NISTs report is an extensive investigation.

NO, it is not more extensive or detailed then the FEMA report.

Put this to a public vote, I don't know what methods there are on ATS for doing so but this is such a ridiculous claim that I feel confident nobody will agree with you.

Originally posted by exponent
FEMAs report was quite speculative and an early look into potential failure mechanisms.

Kind of like the NIST model at the beginning stating that neither the plane impacts or fire casued the collaspe?

Originally posted by ULTIMA1
Kind of like the NIST model at the beginning stating that neither the plane impacts or fire casued the collaspe?

I've explained why you are wrong on this topic several times, you have failed to address this criticism several times. Please re-read my previous posts on the matter.

Originally posted by exponent
I've explained why you are wrong on this topic several times, you have failed to address this criticism several times.

I have posted the quote from the model. Are you saying its wrong?

Originally posted by ULTIMA1
I have posted the quote from the model. Are you saying its wrong?

Your understanding of the modelling process is wrong as I have already explained several times. I have already given you notice in another thread but I no longer intend to reply to any of these posts where you simply repeat your previous statement without any factual backing.

Take it to moderated debate or don't expect any more replies on the same subject.

Originally posted by exponent
Take it to moderated debate or don't expect any more replies on the same subject.

Thanks for proving my point again that believers cannot have adult discussions with evidence.