The NIST report, start to finish

Originally posted by exponent

That's not evidence.

I never said it was evidence. But when there is no evidence either way I'll go with what is physically possible.

The OS is not physically possible, and you can not prove it to be. I can not prove it didn't happen as the OS claims, but common sense, and a smattering of physics knowledge, should raise huge red flags to anyone with an open mind.

In fact there is evidence for it, in that at least 4 different simulations by different groups have now shown it to occur in plane impacts on the towers, even in the most conservative estimates.

Simulations are not evidence either mate. You can make a simulation show anything you want. I have yet to see one that makes physical sense.

Do you really think lightweight trusses can snap massive 4" thick columns in two spots above and bellow the weakest point of the system (where the trusses are fastened to the columns)? You can look at the NOVA simulation and believe that really happened? If you do then I'm afraid it shows your level of understanding.

Let alone then believe that would lead to an ultimate complete global collapse through the path of most resistance ignoring the known laws of motion.

How exactly do you think that your personal incredulity should be believed more than the tests by hundreds of qualified engineers?

It's not personal incredulity, it's known physics. C'mon man this is not the only post you've ever read, you know the physics that is being disputed. You're just playing the typical OSer 'pretend I don't know what you're talking about, so it must be nonsense' game.

BTW Exponent, can you explain why the planes didn't cause the trusses to fail immediately, if it had the energy to sever core columns?

If it did cause trusses to fail why did the truss failures not cause the complete collapse immediately? Why did they have to wait to sag from heat?

If the planes did damage trusses, you have to believe they did if you want to believe they severed core columns, then how did they pull in the core and mesh columns? Also if the core columns were severed, how did they also snap in two places as per the NOVA vid? Or has the severed core columns argument been dropped now?

Can you not see how the whole hypotheses contradicts itself?

Originally posted by bsbray11
It was PLB, who you were talking about agreeing with. If you agree with him then I can only guess you'd be trying to make the same argument.

Are you unable to comprehend someone who agrees with another persons viewpoint, but does not adhere to every single thing they have ever mentioned? It seems that way.

But... the photo was developed with the help of NIST.... and the leader investigator of the NIST report, Shyam Sunder, even describes the very same image as you are staring at it in the PBS documentary that NIST itself was involved with.

Right I see, so you're trying to use this to say it's actually an official NIST image, even though it plainly isn't and was a PBS graphic image.

It was not an official NIST image, and trying to pass it off as one is just dishonest.

Well that's according to you. "What likely happened" to me is a different story, but we're not even going to go there, because opinions about 9/11 are "a dime a dozen" as they say.

Yes, but this is based on someone who's actually read the NIST report, so one hopes I have a better understanding than someone who has not.

Originally posted by ANOK
I never said it was evidence. But when there is no evidence either way I'll go with what is physically possible.

The OS is not physically possible, and you can not prove it to be. I can not prove it didn't happen as the OS claims, but common sense, and a smattering of physics knowledge, should raise huge red flags to anyone with an open mind.

Simulations are not evidence either mate. You can make a simulation show anything you want. I have yet to see one that makes physical sense.

This whole section is just you repeating exactly the same mantra. 'I dont believe it, therefore it isnt possible, people who say it is possible are therefore lying or dishonest'.

This is absolute utter rubbish. The people involved in these simulations include Weidlinger, NIST and Purdue. These are not amateur organisations, and their engineering expertise far outranks your own. You need to have some evidence to start dismissing their results, not just i dont like it.

Do you really think lightweight trusses can snap massive 4" thick columns in two spots above and bellow the weakest point of the system (where the trusses are fastened to the columns)? You can look at the NOVA simulation and believe that really happened? If you do then I'm afraid it shows your level of understanding.

No, I already said that is rubbish and almost certainly a graphic image.

It's not personal incredulity, it's known physics. C'mon man this is not the only post you've ever read, you know the physics that is being disputed. You're just playing the typical OSer 'pretend I don't know what you're talking about, so it must be nonsense' game.

I see, so you're playing the typical truther 'my high school education and limited reasoning about the collapse means my physics theories are unassailable!'

You don't know what you are talking about. That much is clear given that all plane impact studies of the towers show core column damage from the plane, something you say is impossible.

BTW Exponent, can you explain why the planes didn't cause the trusses to fail immediately, if it had the energy to sever core columns?

If it did cause trusses to fail why did the truss failures not cause the complete collapse immediately? Why did they have to wait to sag from heat?

Many trusses did fail, for a number of different reasons, but it was the failure of the outer wall that initiated the collapse, not the failure of trusses.

Can you not see how the whole hypotheses contradicts itself?

No, because I have done more than use my own personal incredulity and the soothing text of conspiracy websites. The only reason you believe their hypothesis contradicts itself is that you do not know what their hypothesis is.

reply to post by ANOK


If someone punches you in the mouth, you may stay standing. If they continue to kick you in the balls you will fall over. Please, use the analogy wisely but it answers your questions.

You are simply either blind or unwilling to understand the words of someone unless they are in agreeing with you and giving you stars for your posts. You can say no as many times as you want but that does not make your argument correct. Hell, you do not even post arguments. You simply tell people they do not have an education or do not understand basic physics.

Nothing is contradictory. You are simply buying into remixed versions of stories for web hits.

Grow a set and defend what you say for a change.

Originally posted by esdad71
reply to post by ANOK

 

You are simply either blind or unwilling to understand the words of someone unless they are in agreeing with you and giving you stars for your posts. You can say no as many times as you want but that does not make your argument correct. Hell, you do not even post arguments. You simply tell people they do not have an education or do not understand basic physics.

Nothing is contradictory. You are simply buying into remixed versions of stories for web hits.

Grow a set and defend what you say for a change.

edit on 3-5-2011 by esdad71 because: (no reason given)

So why don't you build a self supporting physical model such that the top 15% can fall on the rest and completely collapse it by DAMAGING COMPONENTS? None of this house of cards sliding apart business.

A physical model does not give a damn what anybody says. And provide data so anyone can DUPLICATE IT.

www.youtube.com...

psik

Originally posted by esdad71
reply to post by ANOK

 

If someone punches you in the mouth, you may stay standing. If they continue to kick you in the balls you will fall over. Please, use the analogy wisely but it answers your questions.

Why do you insist on making these analogies with the human body? Don't you realise the difference in the physics going on between a human body and a inanimate object?

When did the WTC have balls? Or are you really just making a veiled threat there asdad?

You are not even close to making any sense with that. As soon as anyone compares it to another building, then it's 'oh no different design not even close'.

You are simply either blind or unwilling to understand the words of someone unless they are in agreeing with you and giving you stars for your posts.

Huh? First off stars have nothing to do with anything, obvioulsy they do to you as you bring them up

It has nothing to do with who agrees with who. You have obvioulsy lost the plot, you have nothing to counter the real physics presented by me and others so you resort to this nonsense post. What is the point of this other than wasting everyone's time?

You can say no as many times as you want but that does not make your argument correct. Hell, you do not even post arguments. You simply tell people they do not have an education or do not understand basic physics.

That is because you don't read the posts. I have explained many many time why you don't understand the physics, you prove with your own words you don't understand the physics. I can point them out to you if you need me to.

In fact here is one gem of an example that just shows your knowledge of physics...

Originally posted by esdad71
reply to post by psikeyhackr

 

There are no impossible physics. However, you also cannot pick and choose what applies which is what you are doing. You cannot enforce one part of one law and call it a day.

www.abovetopsecret.com...

No impossible physics? Newtons laws of motion are only one part of the physics? No one was picking and choosing, that is what you do with your 'it was the KE and gravity', and ignore equal opposite reactions and moment conservation laws. You don't realise Newtons laws of motion is what covers all physics to do with motion, including when motion is stopped due to collisions. So don't tell me I don't post arguments.

I tell people they don't understand physics yes, but I explain why, and in the context I say it anyone who understands physics can see I'm right.

Nothing is contradictory. You are simply buying into remixed versions of stories for web hits.

Again nonsense. Where did I read what I said on line? You're just angry because I completely contradicted your whole claim and you have no way to weasel out of it. It's a point I have a feeling you've not thought of before, and you have no idea how to counter it, do you? I mean I just thought of it myself, that's why I posted it.
It's like a DOH! moment, don't you agree?

NIST forgot about the planes damaging trusses huh? Kinda contradicts their hypothesis imo. You can't claim trusses were not damaged anymore than you can say columns were severed. You have a problem my friend.

Grow a set and defend what you say for a change.

What is that supposed to mean lol? Do you ever actually read any of my posts, or do you forget what the ones before the last one you read said?

Could you actually contribute to the post instead of ranting about me personally? Answer the question I posed above. Or does that fall outside of your physics knowledge esdad?

reply to post by -PLB-

Then here we disagree. I can't really see how situation 8c can occur before any diagonal has failed.

I don't see how any of what is claimed is feasible, but that is how the authors describe it, believe it or not. How do you think pull in forces were generated before the diagonal failed?

Ok. But I give the people who actually modeled it and published their results a lot more credit than assertions from an anonymous person on a forum.

Assertions backed up with calculations. Note that the model did not provide calculations proving it was feasible or disclose the internal forces in the members under pull in configurations. You have to take their word for it, but they don't even say what their qualifications are, if any.

The exact wording was "as shown in Fig. 8(c)" and not "as simulated" or something similar.

You have to read it in the context of the entire paragraph I posted. 11.7 minutes was within the simulation.

Ok

My summary will be in my reply to exponent.

reply to post by exponent

I have read the discussion between you and PLB, and frankly I think that it's a little pointless considering that neither of you seem to have attempted to contact the authors and ask these questions.

I'm very confident I have the correct interpretation of the report. What do you believe the case to be?

The only equations I found in previous posts was a list of common calculations for beam deflection, but these require quantities that we have not seen supplied or agreed upon. Could you post these calculations in detail?

Sorry, I should have gone into more detail.

In the following "w" represents "omega", "L represents "l" (lower case "L", in order to make it distinct from upper case "i") and "S" represents "sigma-max". I will also be working in SI units. Here is the link again to the equations.

Rearranging the number 8 equation for S gives:
w=(384SEI)/(5L^4)

Substituting this into the number 8 equation for theta gives:
theta=(384S)/(120L)

L=18.3m (length given in paper, I used 18.0 in my original calc which gave 11.6 degrees)
S=1.143m

therefore theta=0.1999rad
=11.5 degrees

I just don't quite get how you calculated identical angles for non identical deflections for example.

I have assumed the loading specified in the model.

Your calculation was purely a vector one, there was no consideration for catenary behaviour, and yet you used it as justification for criticising the paper.

Vector calculations are how the vector forces of a member in catenary action are obtained.

Frankly, I am finding it difficult to understand exactly what your position is and what you believe supports it. If you would be so kind, please lay out your calculations showing problems with this paper so we can actually discuss it.

Certainly. The deflection calcs above make up the beginning of my argument. Note that I will use the 11.5 degree deflection so my results will differ very slightly to those earlier posted.

~85kN is given as the horizontal component of the max catenary action at the support(rough eyeball from figure 7).

Therefore the vertical component at the support = tan(11.5) x 85 = 17.3kN

The vertical load being applied to one support = 4.8kN/m2 x 2m x 9.15m = 87.8kN

4.8kN per meter squared is the UDL value used in the model. 2m is the width of floor each truss supports. 9.15m is the length of half the truss (each support carries half the load under the loading used in the model).

Therefore 70.5kN of load was not taken by catenary action. Catenary action was claimed to take most of the load but as we can see most of the load is not being transferred to the supports via catenary action, therefore the report and/or model are incorrect.

PLB suggested that maybe there was a mistake in the wording claiming most of the load was carried in catenary action and that the majority may have actually been carried in bending. I don't believe this was the result of the model at all so I won't include the calculations I did here but can dig them up if you wish. I showed that the capacity for this would no way near exist.

reply to post by psikeyhackr


Why don't you...oh, that's right, you do not know how much concrete there was although you have been provided anything. ANOK, an analogy is that, an analogy. Look up the definition. If you do not know what an analogy is then how can you expect anyone to believe you understand physics?

All of you never give your reasons, you just bitch and moan and self declare your perception as truth without any proof ever. It is almost as if you guys take a course but then again, you could not be the disinfo right? Keep people from asking questions about other parts of 9/11 so lets start a conspiracy distraction. You guys do not even realize you are promoting the agenda you are so afraid of.

reply to post by esdad71


That has to be one of the lamest attempts I've seen to try and debunk the reasoning and calculations that ANOK, psikeyhackr, Azp420, bsbray11 and NIcon have been showing you.

It's so obvious that you're out of your depth in this thread, esdad71.

Originally posted by Azp420
I don't see how any of what is claimed is feasible, but that is how the authors describe it, believe it or not.

I would say that is how you interpret it. If your interpretation does not make any sense, that may indicate it is wrong. But I will drop the writers a mail. Although I don't think your argument in the above post is that well written to include in the mail, I may edit it and pm you about it.

How do you think pull in forces were generated before the diagonal failed?

Similar to how the pull in force is generated in a regular I-beam that is in catenary action.

Assertions backed up with calculations. Note that the model did not provide calculations proving it was feasible or disclose the internal forces in the members under pull in configurations. You have to take their word for it, but they don't even say what their qualifications are, if any.

You have not provided calculations that show the pull in force when the truss is intact, only when the top chord is carrying all the load. Since you assert that the force would be negligible, I would like to see what you base that on (other than intuition).

You have to read it in the context of the entire paragraph I posted. 11.7 minutes was within the simulation.

But thats clearly a matter of interpretation. I don't think your interpretation is either obvious or correct.

reply to post by -PLB-

But I will drop the writers a mail. Although I don't think your argument in the above post is that well written to include in the mail, I may edit it and pm you about it.

Cool. Sorry for not writing it a bit better.

Similar to how the pull in force is generated in a regular I-beam that is in catenary action.

In this case the web (vertical piece) of the I beam would be in tension. Thus the analogy doesn't hold when comparing it to a truss which works in a different way and experiences compressive failure in its diagonals.

You have not provided calculations that show the pull in force when the truss is intact, only when the top chord is carrying all the load.

I'm unable to because there are none.

Since you assert that the force would be negligible, I would like to see what you base that on (other than intuition).

By all means, don't take my word for it. Figure 4 of the paper shows the internal forces of the intact truss and the vectors at the supports. As you will see, the horizontal vector is zero.

But thats clearly a matter of interpretation. I don't think your interpretation is either obvious or correct.

I agree that I don't think my interpretation is obvious. I only arrived at it after very carefully reading it through. If the authors described the events in chronological order it would have made interpretation much easier for all.

Originally posted by Azp420
In this case the web (vertical piece) of the I beam would be in tension. Thus the analogy doesn't hold when comparing it to a truss which works in a different way and experiences compressive failure in its diagonals.

I don't follow you here. You ask how a truss could exert a pull in force when the diagonals have not failed. I respond that it would behave similar to an regular I-beam. Then you respond that this is incorrect because the truss will experience failure of its diagonals. But the premises is that the diagonals have not yet failed. Sure, after they fail the truss does not behave similar to an I-beam anymore, but before they fail it does.

I'm unable to because there are none.

Well, get to work then . It would disprove NIST.

By all means, don't take my word for it. Figure 4 of the paper shows the internal forces of the intact truss and the vectors at the supports. As you will see, the horizontal vector is zero.

I am sorry that I was not clear. I used the word "intact" but by that I meant that none of the members had failed, not that it was in its original shape. Figure 4 shows the truss in the situation it is not heated so there is no centenary action. When the truss is heated figure 4 is no longer valid, and needs to be recalculated including the expansion in the members, deformation, and the yield strength at that temperature. It seems to me that is not an easy thing to do, that is why the writers of that paper used simulation software. And their result is shown in figure 7.

So on what exactly do you base the assertion that a heated truss without any failed members exerts a negligible inward pull force?

Originally posted by tezzajw
reply to post by esdad71

 

That has to be one of the lamest attempts I've seen to try and debunk the reasoning and calculations that ANOK, psikeyhackr, Azp420, bsbray11 and NIcon have been showing you.

It's so obvious that you're out of your depth in this thread, esdad71.

The majority of the time, the reasoning that is done by the people mentioned is based on faulty ideas and misconceptions due to the scale of the towers and how nobody has ever seen anything like 9/11 happen before. I'd say that Azp420 is so far the only person I've seen doing real calculations, though he has also fallen for many of the lies and disinformation webs on the internet. 9/11 Truth is often about convincing the other side that it was a conspiracy through rhetoric, making it look like you have more evidence than you do. You say you're just asking questions, but then you say "Well, if this is true, then this might be the case," and in that way, the lies are indoctrinated in the subconscious of the viewers (which is why the youtube videos are so effective). I feel like a lot of people here are literally brainwashed sometimes.

reply to post by -PLB-

I don't follow you here. You ask how a truss could exert a pull in force when the diagonals have not failed. I respond that it would behave similar to an regular I-beam. Then you respond that this is incorrect because the truss will experience failure of its diagonals. But the premises is that the diagonals have not yet failed.

The diagonals have not failed in compression YET. The analogy is invalid because you are comparing a beam which has pure tension in the web to a truss, which your model claims has compression building in the compressive diagonals. These two things carry loads in different ways. If you want to prove that a truss can generate a pull-in force then show what some example internal forces in a truss would be. Showing what can happen in a beam proves nothing.

Well, get to work then

. It would disprove NIST.

I can't . There's not a structural engineer in the world that doesn't already know this.

I am sorry that I was not clear. I used the word "intact" but by that I meant that none of the members had failed, not that it was in its original shape.

No matter what the deflection, if none of the members have failed, the truss is unable to generate pull-in force under this loading configuration.

And their result is shown in figure 7.

It is a pretty graph, but a much, much more informative result would be a diagram similar to fig.4.

So on what exactly do you base the assertion that a heated truss without any failed members exerts a negligible inward pull force?

The top chord cannot be in tension without transferring it to the bottom chord and putting that in compression. If the top chord is in tension and the bottom in compression it is not carrying anything in bending. The report is really not claiming this at all, try to read the entire section again very carefully.

I have also been unable to find any other documented cases of this behavior (perhaps someone has has been more successful searching than me?). This phenomenon occurring in trusses never got a mention at any point in my education. I'm aware 9/11 was unique, but fires are not that unique. The fireproofing was blown off you say? Most fire proofing is not designed to offer much protection after about two hours anyway, and I'm sure there have been many fires around trusses lasting longer than that, or fires where trusses weren't fire proofed. I'm aware this is not proof, I'm just offering it for interests sake.

reply to post by Varemia

I'd say that Azp420 is so far the only person I've seen doing real calculations, though he has also fallen for many of the lies and disinformation webs on the internet.

I can assure you that any claims are carefully passed through my structural engineering knowledge and checked for BS.

in that way, the lies are indoctrinated in the subconscious of the viewers (which is why the youtube videos are so effective).

As opposed to television, right? Because the mainstream media would never be anything but completely impartial and honest.

I feel like a lot of people here are literally brainwashed sometimes.

This feeling is mutual across both camps. It's hard for humans to come to terms with how people can hold greatly differing beliefs to their own. I've been coming more and more used to this as most of my major beliefs are the opposite of popular opinion.

reply to post by Azp420


Exactly. That's why as an Anthropology student, I've been deciding slowly to just let people be here. You hold a different worldview than I do, and nothing that anyone says or proves will change anyone's mind, because a lot of the conspiracy relies on specifically a "lack" of evidence. You can't prove a negative. That's why theists fight with atheists all the time. Each one is trying to prove a negative. One is trying to prove that God doesn't exist (impossible) while the other is trying to prove that God can't not exist (also impossible).

reply to post by tezzajw


That's it? No contribution? Just again someone saying that I know less than the other posters because I do not conform to your thoughts. Any thread that is started is eventually derailed by those you named by badgering anyone who does not agree.

Debate. Lets do it. I have stated this many times and invited any of you to a formal debate. I went as far as to schedule it with the mods when that person would not and it went nowhere.

You cannot prove your theories with physics or else you would. You all simply say it has never happened like this before or simply quote anything from GLP.

Add something about the NIST report that disproves it.

reply to post by ANOK


Wrong. I am going deeper into the laws than you do and you know it. Go back in the threads and you you reuse some of the information I post as if you are learning something.

You have proven nothing. You are stating thoughts and not facts. How about a private debate on 9/11? Just me and you strawman...any subject you want...

as far as threats, I did not make threats so I apologize for how you feel.

Now, please explain this to me....you said

Why do you insist on making these analogies with the human body? Don't you realise the difference in the physics going on between a human body and a inanimate object?

Please explain the physics here? Are you now stating that physics in conjunction with a human body react differently then buildings. I am using the analogies as if I was talking to a child to help them understand basic physics.

Can you please also answer one question? What do you feel NIST was supposed to do during the investigation.