Chemistry/Physics Behind the Attacks

Originally posted by Phoenix
Now that you have demonstrated that the panels could move outwards into open air, can you please explain in clear language how panels with a 2" gap between it and the column moves inward without the column moving also.

I was demonstrating to Howard that the panels could move very easily without regard to the columns they cover.

Regarding the second NIST photo, I seriously doubt that it is honest in its presentation of *heat* damage to those columns. There was damage from the jet impact in that region. I will accept that those columns were bent from the jet impact, but not from the fires. I'll have to see some evidence to support that assertion, and not just more assertions.

Originally posted by Valhall
This shows that 7 floors (70 feet) had collapsed on the east side of the building - that would be seven floors that the west side of the building would have to "catch up to" while being in a decreased state of compressive load.

A minor thing, but each floor was about 12 or 12.5 feet high rather than 10, which is, I'm assuming, what you used in your calculation here. I would double-check though, because I could be wrong. I did a quick Google search, and those figures seem to come from dividing the height of a tower by the number of floors, but I think there's more to take into account than that.

Originally posted by HowardRoark
Since there was no lateral stability in the core, it would not have put up much resistance to the collapse.

Since when does NIST assert lateral forces were to blame for global collapse? Down apparently has to be sideways for your claims to be valid, because the vast majority of the forces there would have been vertical.

In fact, what does NIST say at all regarding the global collapses? Not much of anything. They go into a lot of detail on how they think the collapses initiated but that's it. No modeling or other information on how global collapse took place, other than a vague reference of an "inevitable" pancaking.

Originally posted by Jack Tripper
What is your conclusion from all this Valhall?

Are you coming to the obvious and simple conclusion that Professor Jones came to when he said this defied the Law of Increasing Entropy?

Yes. But I'm in the early stages of analyzing it. Intuitively this violates inertial laws. This pic and the statements I've quoted before from the NIST have convinced me the collapse could be unnatural. I'm riding the fence in search of the facts. Maybe we can get there through our own analysis. At least we'll have confidence in the assumptions we make.

Originally posted by bsbray11

A minor thing, but each floor was about 12 or 12.5 feet high rather than 10, which is, I'm assuming, what you used in your calculation here. I would double-check though, because I could be wrong. I did a quick Google search, and those figures seem to come from dividing the height of a tower by the number of floors, but I think there's more to take into account than that.

Thanks bsbray for double checking me! But I did, in fact, use 12 feet. The confusion came from me saying 7 floors. Sorry about that, it would be 6.



[edit on 2-21-2006 by Valhall]

Originally posted by HowardRoark
Nice drawing.

I think from that it would be pretty clear that the core area of the lower portion of the building would be subjected to sideways forces as the top came down. Since there was no lateral stability in the core, it would not have put up much resistance to the collapse.

Sorry, Howard, I missed this post.

I can't agree with that at this time. I think the core columns, under this much bending load would have snapped at the end plate connections. I don't think there was anything effecting the lower half of the building. But it's too early in the analysis to get all confident about that. Some times things turn out to be counterintuitive and I realize that. I think the numbers will tell.

[edit on 2-21-2006 by Valhall]

Originally posted by Valhall







And thank you very much! I really don't have any theory, so I'm open to consideration of just about anything! lol I'm just trying to find out for myself if these damned buildings could fall as they did, naturally. So, if you see something I tended toward that looks like a bad assumption, or a bad calculation, etc. PLEASE POINT IT OUT! I don't want to waste my time on errors.

I started with hand calculations on a 2D shotgun approach, but now I'm going to go to 3D modeling starting with very gross primitive looks at movements (say the angle of the top and getting straight in my mind what all that means to us on a gross level). Then I'd like to start modeling individual structural components and work out a good model that we all agree on. Because if we can't agree on the model, then we'll just keep arguing - for the sake of arguing. lol.

So, what I thought is that I would just check in every step of the way. That way if anybody sees me doing some wrong, they can catch it on that step, and we can work together (no matter what side of the fence a given person may be sitting on - I'm straddle it right now LOL) they can have a voice in it.

SO! In answer to your question(s) - I DON'T KNOW RIGHT NOW! But hopefully we can find out together! Which is kind of an exciting adventure, isn't it?

Thanks for the reply Valhall and sorry it is taking so long to get back to you.
(dang day job gets in the way of all this fun)

Questions, questions, questions

The 3D model with an intact core would show what plane line the tipping occurred at - from the center mass fulcrum going generally north south angled off center - hope thats clear?

It seems to me in concept that to have tipping (even mere inches) then many columns on the SE can be said not to be supporting much gravitational load. Conversely the same could be said for the NW columns in tension (not 100% unloaded though)

Therefore much of the gravitational load must have been supported for a brief time on the core and columns along the plane line of the fulcrum running north south, if that is surmised to be the case then I would guesstimate that for a short time as little as 30% - 40% of available structural columns may have supported a high majority of the gravitational weight.

This would go a long ways in explaining some of the physics involved in subsequent explosive appearing collapse.

Then the action left to prove or explain to a point of no reasonable doubt would be the root cause of the tipping action in the first place.

Does that make any sense to you or help in formulation?

Seems that once the line of fulcrum is established by 3d then it would not be too difficult to compute tension and compression on exterior columns as the moment increases away from the line two or three calcs either direction would provide a distance/force ratio I think? Also I would be more apt to calculate with the initial 1/4 or 1/2 degree of motion - I think any structural element anywhere near the fulcrum line would show severe overload.

Check me - let me know your thoughts

Phoenix

Yes, I think I'm following you.

I agree that we want to actually go with a fully intact building (subsection - we can't model the entire 110 stories, we'll have to pick some manageable chunk) and then remove the structural elements identified by NIST. Then we'll start applying thermal effects and let the building move as it wants.

I'll have to get DesignSpace reloaded. My harddrive crashed two weeks ago and I'm not fully reloaded on my programs. But in the meantime, it's going to take quite a bit of time to model up everything in SolidWorks anyway. If I can pull it off, I'll get a full-blown ANSYS done, but my access to that will be limited. The DesignSpace I can do on my own.

I contacted a metallurgist yesterday and have obtained some various graphs that will be applicable for the thermal degradation and creep. So we can incorporate that data. And I will disclose all graphs and data I'll use so that anyone can look them over and say yay or nay over them. But I have had quite a bit of metallurgical experience myself over the past 15 years, and I have a lot of confidence in the metallurgist I'm working with. In addition, I have access to MIL-HNDBK-5 which is pretty much the bible for thermal effects.

If the model becomes so complex I can't run it on my own machine, we'll punt and pass it off to some one with a workstation and full ANSYS. We'll get it done.

Valhall, I did some checking of what the definition of lightweight concrete is in a Universal Building Code (UBC) book, it is defined as that which weighs less than 115 pound per cubic foot - it depends on aggregate type used more than anything - larger generally means lighter weight.

The sheetmetal decking can be assumed to be 4X6 inch trough, the oft quoted 4 inch depth of concrete would normally be measured from top of decking to top of concrete leaving room for reinforcing mesh or rebar.

This means an average depth of 6 inchs.

The floors were generally 43,200 square feet and penetrations for elevators, utilities and other shafts would reduce the concrete decked area to 36,720 using a 15% factor.

The live load out in the open areas was 50psf (I'll not use the 100psf for core area to keep this simple, makes the number more conservative anyway)

Concrete = 57.5 psf
Live load = 50.0 psf
Total = 107.5psf

107.5 X 36720 = 3947400 pounds or 1790204 kg

This weight does not account for truss weight, metal decking nor weight of vertical columns, it is still a very conservative number. I think the true weight may have been over 4.3 million pounds when all is taken into account. HR may know steel weight to add into the calculation.

Thanks Phoenix!

Steel is .283 lb/cu.in. But SolidWorks incorporates the mass properties of the material you're using, so once I model something, it will automatically calculate that for us.

[edit on 2-21-2006 by Valhall]

Originally posted by Valhall
Thanks Phoenix!

Steel is .283 lb/cu.in. But SolidWorks incorporates the mass properties of the material you're using, so once I model something, it will automatically calculate that for us.

[edit on 2-21-2006 by Valhall]

Thanks Valhall, wish i had access to the toys...em hmmm tools that you have.

Here's a real important slide from the NIST site. It caps the temperature of the core columns in WTC 2 at 200 to 250 C.

Here's our first core column. I'm naming it 504 from 2-7 of the NIST document.



This link will open an image that has the total model (30 foot length) and mass properties for the model. (Too big to post in thread).

www.abovetopsecret.com...

This shows the columns that I am assuming to be the same as column 504.



Please let me know if you object to anything in this post. The best time to get agreement is prior to assembling things.

I'm glad you're looking into this Valhall. I tried to come to somekind of conclusion when analysing the core columns but couldn't put enough together to be for certain what the core column configuration was. I hope you find something that I missed and we can find out the arrangement.

I'm going from memory but aren't there three different types of core columns? I ask this because it would be alot easier to identify what is what if there were only two types.

I'm eagerly awaiting your results Valhall. Thanks for your effort.

Griff,

All the info is NOT there. But this is what I'm going off of:



The placement is based mainly on symmetry of design. But I'm going to keep posting all my assumptions so that if anybody has more detailed info that shows I've "picked wrong" we can quickly correct it.

I'll let ya know if what you get is close to what I have. It's hard to just make guesses. This is one of the reasons why I think NIST is hiding something. They won't tell us which columns were where and all. Like I keep saying...if there's nothing to hide, why are they hiding everything?

There is a lot of info in the appendixes. It is in scanned format so you have to go through it a page at a time.

Originally posted by HowardRoark
There is a lot of info in the appendixes. It is in scanned format so you have to go through it a page at a time.

Could you please provide the link to the appendices? I find the NIST site hard to find things on. Thank you.

Next column modeled...701:


www.abovetopsecret.com...

Physics is not my strong suit... can anyone explain why a building that is being imploded would fall faster than a building that is collapsing? Thanks.

The only thing I have to chime in here is that we should keep in mind that we're doing the best we can with the available data (er, you're doing the best you can anyway; I'm not qualified), and that the information NIST has and is providing may be way off.

external image

Those columns from Ground Zero seem much bigger than any of the core columns NIST tells us about, and yet how do we know that no such columns were present on the relevant floors?

Or just below them? Then NIST wouldn't have to mention them at all, because they only try to explain collapse initiations in their report and only refer to global collapse as "inevitable" without any further information.

Basically I don't trust NIST, and it really annoys me that they're so stingy with info when they have the freaking construction drawings right in their faces. It seems that the best we can do here is about equivalent to getting average floor weights and applying them to the lightest floors, or having to compare the Twin Towers to other skyscrapers just to get an idea of how much they even weighed: we could be much more accurate with more accurate information.

If I'm interpreting the information in the report inaccurately then feel free to enlighten me, but it really seems like they're not giving a rat's ass worth of info on the very subject they spend so many pages trying to map out for us: how collapse initiation was allowed. Knowing exactly where each column was where seems like it would be pretty important information to me, personally, if they want to be taken seriously and reviewed seriously.

Originally posted by craig732
Physics is not my strong suit... can anyone explain why a building that is being imploded would fall faster than a building that is collapsing? Thanks.

It would all depend upon the amount of resistance, whether it be from steel or air or etc. I think, in implosions, a vacuum can be created in which there is no appreciable resistance from even air. I don't think that the WTC Towers were brought down in any such fashion, though. Maybe WTC7, but not the Twin Towers.

the billiard ball analogy, from 'janedoe'

i started a seperate thread, because i think this argument, if sound, renders all other factors obsolete, and i don't want to derail this line of discussion.

please visit and comment.

(really, it's because i'm a point hound. give me points! i love points!! )

[edit on 23-2-2006 by billybob]

Originally posted by bsbray11


external image

Those columns from Ground Zero seem much bigger than any of the core columns NIST tells us about, and yet how do we know that no such columns were present on the relevant floors?

Or just below them? Then NIST wouldn't have to mention them at all, because they only try to explain collapse initiations in their report and only refer to global collapse as "inevitable" without any further information.

Basically I don't trust NIST, and it really annoys me that they're so stingy with info when they have the freaking construction drawings right in their faces. It seems that the best we can do here is about equivalent to getting average floor weights and applying them to the lightest floors, or having to compare the Twin Towers to other skyscrapers just to get an idea of how much they even weighed: we could be much more accurate with more accurate information.

We are in agreement on the stinginess. Since the NIST investigation was paid for by taxpayer funds, every bit of data to completely verify the methodology should have been provided with the final report. Detailed blueprints, everything.

They do make a type of hand-waving statement concerning the lower floor core columns:

The columns in the lower floors were primarily huge box columns as large as 12 in. by 52 in. composed of welded plates up to 7 in. thick.

wtc.nist.gov... (page 10)

But they also give transition floors for where the core columns transition from box columns to wide-flanged i-beams, but don't give the transition floors for when a core box column transitions to a lighter (thinner walled) box column. All that information should be available to anyone reviewing the analysis.

The box columns you show there look to be about 2 inches thick plate (just guessing that based off comparing to the 2X? separating the two beams. They are also rectangular and if you notice up in the diagram I pulled from the NIST report - that cross section isn't depicted.

CORRECTION: 12m8 convinced me I was wrong. Those are 4 X somethings...so the plate those columns are made of appear to be about 4 inches thick.

[edit on 2-23-2006 by Valhall]