'What about building 7'?

[Animal]

. Each simulation is unique and depends on accurate data and analysis. If it is based on inaccurate data or omission of data it is not valid.

Completely false. Either you are woefully ignorant with regard to computer simulations of structural modeling, or are simply being dishonest.

 

[pgimeno]

Wouldn't have needed to be done before announcing what the outcome of it would be? Is that scientific?

This deserves to be highlighted.

 

[JayUtah]

This deserves to be highlighted.

Ugh, and corrected for grammar.

 

[pgimeno]

The inexcusable omission of the word "that" invalidates the whole argument

 

[LSSBB]

No. Standard engineering practice requires omission of some elements sometimes. You should know that by now. Let me quote a few examples:

Break elements were used on the east side of Floors 7 to 14, where the fires were dominant prior to collapse. Including break elements at every connection location on these floors would have greatly increased the model size and affected the rate of solution convergence. Since the collapse of WTC 7 clearly initiated on the east side of the structure (Chapters 5 and 8), the break elements were only used in the east side of the model.
​

(NCSTAR 1-9 pp. 457-458)

A procedure was developed for addressing buckled and/or failed components so that any member that did not structurally contribute to the response of the building was removed from the analysis to improve computational efficiency and avoid convergence problems. This procedure was used to modify the model at the end of each 30 min interval, or as necessary when the analysis halted due to non-convergence.
​

(op.cit. p.487)

In the ANSYS analysis, buckling of flexural members led to convergence difficulties. To improve analysis progress, buckled members were removed from the analysis.
​

(op.cit. p.487, bottom)

It's up to you to prove that the intent was nefarious. So far NIST has done well justifying their omission: it was not a failure mode contemplated in the model.

It appears to me based on the pronouncements I have seen that Ziggi has an incomplete grasp on what "solution convergence" means.

 

[Dave Rogers]

This is a silly game. Conspiracy theorists will always reject the NIST hypothesis because it isn't "proved," and it never will be since there weren't any cameras inside the building. The game is to avoid the question: What hypothesis is more plausible, and why is it more plausible? There could be many, but I don't see "magical silent, fireproof explosives" on the list.'

It's even sillier than that. The purpose of the NIST analysis was not to determine whether WTC7 could have collapsed due to fire damage - a point that was never seriously in dispute except from those ignorant of the most basic details of structural engineering and materials science - but rather how it actually did collapse due to fire damage. Even if NIST's model turned out to be invalid, that would simply mean that they had not identified the actual failure mechanism, not - as conspiracy theorists seem to choose to believe - that no plausible collapse mechanism could have existed.

The whole argument over the NIST model is simply a classic example of the typical behaviour of conspiracy theorists; they seek not to resolve the dispute, but simply to continue arguing a worthless position in order to give the illusion that a valid dispute exists. And that's why, however much this thread may appear to be a constructive and informative debate between supporters of two sides of an unresolved question, it is in reality nothing more than another pointless waste of time.

Dave

 

[beachnut]

This is ridiculous and you know it. Running a stat analysis is nothing like setting a computer model simulation of a structure or event. Each simulation is unique and depends on accurate data and analysis. If it is based on inaccurate data or omission of data it is not valid.

Again, if you or anyone else here feels like they can support NIST´s assumption of 6.25 inches of displacement, please take a few minutes and do just that.

What data was omitted, and why does it matter? Gee, you are not acting like an engineer. A model is simplified and "stuff" is omitted. When we do EOM for flight, we discard "data", like the lift associated with the earth's rotation, it is negligible, so we drop it for flight below MACH 3. Thus you are flying in aircraft with autopilots and systems based on "inaccurate/omission of data", and you have no idea why.

Please stop exposing a hate of knowledge and engineering by butchering science.

Sad you can't prove your point, using words will not hack it, and then more sad, it does not matter if you could prove your claims; WTC 7 cause of collapse due to fire, remains fact.

Don't fly, the autopilots and systems have "data" left out... omg - you should see the EOM for flight, it took up the whole lecture room walls... good luck with the woo of 911 truth, now in the 14th year of celebrating ignorance and BS.

 

[DGM]

The whole argument over the NIST model is simply a classic example of the typical behaviour of conspiracy theorists; they seek not to resolve the dispute, but simply to continue arguing a worthless position in order to give the illusion that a valid dispute exists. And that's why, however much this thread may appear to be a constructive and informative debate between supporters of two sides of an unresolved question, it is in reality nothing more than another pointless waste of time.

Dave

This is all they got. They can't present their work in engineering circles because they've done no real work.

Their best so far was to send a DVD to the US Department of Commerce threatening to tell on the NIST to the Europeans.

 

[LSSBB]

It's even sillier than that. The purpose of the NIST analysis was not to determine whether WTC7 could have collapsed due to fire damage - a point that was never seriously in dispute except from those ignorant of the most basic details of structural engineering and materials science - but rather how it actually did collapse due to fire damage. Even if NIST's model turned out to be invalid, that would simply mean that they had not identified the actual failure mechanism, not - as conspiracy theorists seem to choose to believe - that no plausible collapse mechanism could have existed.

The whole argument over the NIST model is simply a classic example of the typical behaviour of conspiracy theorists; they seek not to resolve the dispute, but simply to continue arguing a worthless position in order to give the illusion that a valid dispute exists. And that's why, however much this thread may appear to be a constructive and informative debate between supporters of two sides of an unresolved question, it is in reality nothing more than another pointless waste of time.

Dave

I think that's why, prior to his latest suspension, MM focused on the issue of lack of demolition explosives. That is why NIST ruled out explosives. The collapse simulation is irrelevant to CD. However, if they were thinking more rationally in the first place they would have focused on LIHOP and not gone "full retard" (apologies to anyone that term offends).

 

[gerrycan]

No. Standard engineering practice requires omission of some elements sometimes. You should know that by now. Let me quote a few examples:

Break elements were used on the east side of Floors 7 to 14, where the fires were dominant prior to collapse. Including break elements at every connection location on these floors would have greatly increased the model size and affected the rate of solution convergence. Since the collapse of WTC 7 clearly initiated on the east side of the structure (Chapters 5 and 8), the break elements were only used in the east side of the model.
​

(NCSTAR 1-9 pp. 457-458)

A procedure was developed for addressing buckled and/or failed components so that any member that did not structurally contribute to the response of the building was removed from the analysis to improve computational efficiency and avoid convergence problems. This procedure was used to modify the model at the end of each 30 min interval, or as necessary when the analysis halted due to non-convergence.
​

(op.cit. p.487)

In the ANSYS analysis, buckling of flexural members led to convergence difficulties. To improve analysis progress, buckled members were removed from the analysis.
​

(op.cit. p.487, bottom)

It's up to you to prove that the intent was nefarious. So far NIST has done well justifying their omission: it was not a failure mode contemplated in the model.

Whether the intent was nefarious or not does not trouble me too much. How accurately the buildings response to the imposed conditions does though.
The judgement that an element such as this girder had failed and would therefore be removed (as would every beam connecting to it in this particular instance) was determined outside of ansys and that determination was applied to the ansys model. The stiffener plates should have been accounted for in NISTs initial assessment and that determination applied to the model. To account for the presence of the plates and the difference they would make to the analysis is not a problem for ansys. Whether the decision not to account for these plates was nefarious or just a mistake has no bearing on the accuracy of the report. The difference that the accounting for these plates would have made does not depend on the intention of NIST and we know from them that these plates was not considered.
I don't see a great amount of data being saved by not accounting for the stiffener plates and even if it was a potentially data intensive issue to include them, I don't see how anyone could argue against their inclusion given that this is the connection at the heart of NISTs hypothesis.
As for the failure mode not being contemplated in the model, I agree with you there.
The difference that these plates would have made to the connection was not contemplated by NIST. They have admitted the exclusion of elements without justifying the decision not to account for them in the analysis.

 

[beachnut]

Whether the intent was nefarious or not does not trouble me too much. How accurately the buildings response to the imposed conditions does though.
The judgement that an element such as this girder had failed and would therefore be removed (as would every beam connecting to it in this particular instance) was determined outside of ansys and that determination was applied to the ansys model. The stiffener plates should have been accounted for in NISTs initial assessment and that determination applied to the model. To account for the presence of the plates and the difference they would make to the analysis is not a problem for ansys. Whether the decision not to account for these plates was nefarious or just a mistake has no bearing on the accuracy of the report. The difference that the accounting for these plates would have made does not depend on the intention of NIST and we know from them that these plates was not considered.
I don't see a great amount of data being saved by not accounting for the stiffener plates and even if it was a potentially data intensive issue to include them, I don't see how anyone could argue against their inclusion given that this is the connection at the heart of NISTs hypothesis.
As for the failure mode not being contemplated in the model, I agree with you there.
The difference that these plates would have made to the connection was not contemplated by NIST. They have admitted the exclusion of elements without justifying the decision not to account for them in the analysis.

Ziggi has no theory, do you?

Where is your engineering explanation for WTC 7? Where is your theory? What is the problem, can't you explain your theory? Deets ignored the penthouse collapsing, which is why WTC 7 fell at g for a second or two, the interior had collapsed for 6 second prior to the exterior; can you answer deets question? Do you know what the OP was?


Notice you and Ziggi can't answer the most important questions.

Where is your engineering explanation for WTC 7? Where is your theory? What is the problem, can't you explain your theory?

You can't answer, you have nothing, backed up with no evidence.

 

[DGM]

Whether the intent was nefarious or not does not trouble me too much. How accurately the buildings response to the imposed conditions does though.

Do you agree that protection of the fire proofing/suppression systems is critical in preventing the collapse of a tall building or do you believe they can't fail? Building 7 lost most of this due to the collapse of the towers.

Does the statement; "The building out performed code" sound right to you?

 

[LSSBB]

Whether the intent was nefarious or not does not trouble me too much. How accurately the buildings response to the imposed conditions does though.
The judgement that an element such as this girder had failed and would therefore be removed (as would every beam connecting to it in this particular instance) was determined outside of ansys and that determination was applied to the ansys model. The stiffener plates should have been accounted for in NISTs initial assessment and that determination applied to the model. To account for the presence of the plates and the difference they would make to the analysis is not a problem for ansys. Whether the decision not to account for these plates was nefarious or just a mistake has no bearing on the accuracy of the report. The difference that the accounting for these plates would have made does not depend on the intention of NIST and we know from them that these plates was not considered.
I don't see a great amount of data being saved by not accounting for the stiffener plates and even if it was a potentially data intensive issue to include them, I don't see how anyone could argue against their inclusion given that this is the connection at the heart of NISTs hypothesis.
As for the failure mode not being contemplated in the model, I agree with you there.
The difference that these plates would have made to the connection was not contemplated by NIST. They have admitted the exclusion of elements without justifying the decision not to account for them in the analysis.

Do you know what solution convergence means?

 

[Animal]

Whether the intent was nefarious or not does not trouble me too much.

BS - The NIST intentionally skewing the results to hide CD is what rpops up the troofer religion.

How accurately the buildings response to the imposed conditions does though.

No......troofers will not rest until CD is the only accepted reason

The judgement that an element such as this girder had failed and would therefore be removed (as would every beam connecting to it in this particular instance) was determined outside of ansys and that determination was applied to the ansys model.

And you have no clue why......yet you still harp about it.

The stiffener plates should have been accounted for in NISTs initial assessment and that determination applied to the model.

Only to troofers. The 99.99 percent of real professionals have no issue with it.

To account for the presence of the plates and the difference they would make to the analysis is not a problem for ansys. Whether the decision not to account for these plates was nefarious or just a mistake has no bearing on the accuracy of the report.

Close but no cigar. It wasn't the "decision" the fact they were not included in the analysis had NO bearing on the conclusions of the study.

The difference that the accounting for these plates would have made does not depend on the intention of NIST and we know from them that these plates was not considered.
I don't see a great amount of data being saved by not accounting for the stiffener plates

And your ignorance with regard to building structures and computer modelling is widely recognized.

and even if it was a potentially data intensive issue to include them, I don't see how anyone could argue against their inclusion given that this is the connection at the heart of NISTs hypothesis.

More cluelessness.......it was not know to be "the heart" unitl the end of the modeling. Only troofers reach a conclusion first and then work backwards. The real world doe not operate that way.

As for the failure mode not being contemplated in the model, I agree with you there.
The difference that these plates would have made to the connection was not contemplated by NIST. They have admitted the exclusion of elements without justifying the decision not to account for them in the analysis.

Another troofer lie.

 

[gerrycan]

Where's the explanation as to how the girder framing into c79 from the west manages to push the column to the east, and what is more managed to do it without damaging its connections at all at either end. This should be addressed.

 

[DGM]

Where's the explanation as to how the girder framing into c79 from the west manages to push the column to the east, and what is more managed to do it without damaging its connections at all at either end. This should be addressed.

Explain why.

Come on, you have a team of engineers. Impress us.

 

[Animal]

Where's the explanation as to how the girder framing into c79 from the west manages to push the column to the east, and what is more managed to do it without damaging its connections at all at either end. This should be addressed.

 

[Spanx]

I don't know why these ae911 experts don't save up and have a road trip to visit the NIST.

They could ask all their questions instead of posting on conspiracy forums.

Although I dare say the end result would be them coming out saying they have been lied to

 

[Spanx]

Duplicate

 

[Dave Rogers]

Do you know what solution convergence means?

To be fair, that's quite an esoteric question. You'd only expect someone with actual experience of FEA to be able to...

Oh. Right. I see what you did there.

Dave