"Amateur Engineering" practice in progressive collapse analysis[W:222, 344. 1463]

[Sadling]

re: "Amateur Engineering" practice in progressive collapse analysis[W:222, 344. 1463]

huh?

the top of the tower was destroyed before it fell 20 floors, I already showed you that.

In other words there has to be a top to pile drive and there was none.

Agreed. The only point I was making with my question was to point out that the loss of the steel and debris seen being expelled laterally from the beginning of collapse would take away from the idea of the top block acting as an irresistible force on the undamaged part of the building below.

 

[KokomoJojo]

re: "Amateur Engineering" practice in progressive collapse analysis[W:222, 344. 1463]

Or, you can reinterpret the term 'pile driver' literally as a pile (of debris) driving the collapse. A rubble-driven collapse. Mass is not lost because an assembly disintegrates. It does take energy to break things, and it does change the character of the collapse mechanism in a big way. An ensemble of objects will not deliver the same peak force in impact as a single (rigid or semi) body with the same net mass/momentum. Does this mean arrest is inevitable? I certainly know of no law of nature which says so.

I do know there are physical laws which dictate that a floor assembly could not support even the mass of the upper section statically, distributed for optimal loading. The floors would fail under this weight, and all that's below to stop this is the same kind of floor assembly which couldn't hold the weight of one less floor. Clearly if a debris field of sufficient mass to fail a floor in static, uniform loading, were to impact a floor in a suboptimal geometry, the floor will fail and will do so no later than the point where all mass has accumulated on the floor.

But, as I said, a rubble-driven collapse will have different characteristics. You are trying to claim a rubble-driven collapse is impossible without justification. There does not have to be a pile driver. There only needs to be overloading of floor assemblies for continued collapse progression. If the floors are destroyed, the perimeters will lose lateral support, and will likely also experience lateral pressure from an ever-increasing volume of - ahem - provably unstoppable debris. This might cause the perimeters to fall outward. Well, what do you know? They did.

it was a solid nondisintegrating block falling between to walls of blocks simply stacked on top of each other. What else would you expect?


Now what I and most engineers would expect is:



You have to love the way the columns stick right on through the roof.

see it just falls right on over the side.

See how grossly insufficient discussing one lousy column and comparing it to a structure of many interconnected columns is yet?

 

[psikeyhackr]

re: "Amateur Engineering" practice in progressive collapse analysis[W:222, 344. 1463]

Wouldn't it also be virtually impossible to calculate the loss of the pile-driver effect due to the cascading steel and debris seen outside the perimeter of the Towers as seen in videos of their collapses?

That is part of why I keep talking about making the structure AS WEAK AS POSSIBLE.

Duplicating the mass distribution of the WTC and then making the supports at each level AS WEAK AS POSSIBLE Would mean that if it still fails to collapse then the supposed collapse of the north tower would be extremely questionable without some other power source involved in destroying the supports.

We know skyscrapers are not designed to be as weak as possible. So I think the loss of mass outside the perimeter would be irrelevant to the test.

psik

 

[psikeyhackr]

re: "Amateur Engineering" practice in progressive collapse analysis[W:222, 344. 1463]

Now what I and most engineers would expect is:

Who are these most engineers?

And how was that graphic made?

psik

 

[KokomoJojo]

re: "Amateur Engineering" practice in progressive collapse analysis[W:222, 344. 1463]

Who are these most engineers?

And how was that graphic made?

psik

I have lots of friends

 

[Kat Dorman]

re: "Amateur Engineering" practice in progressive collapse analysis[W:222, 344. 1463]

it was a solid nondisintegrating block falling between to walls of blocks simply stacked on top of each other. What else would you expect?

Nothing I said in the post you quoted had anything to do with the solid model. Not a word of it. Are you replying to the wrong post?

Now what I and most engineers would expect is:

That's nice. Another game physics engine used in lieu of the money or expertise to use a real FEA tool. I stopped doing 3D entirely in a physics engine, even for simple stacks of slabs, and went to 1D and not too many bodies. These environments are not made for physical simulations this complex. Many are designed to fudge physics realistically because GAMES can't spend 1hr real time calculating 1 second of sim time. Properly applied, they are at best useful for studying simple systems, as I've done.

Just because it jibes with what you expect doesn't mean it represents reality. Chances are it doesn't. I love the totally unphysical actions of the free debris off to the side taking off like rockets. That's "fizix", hahaha!

My physics engine experiments are far more modest, in keeping with intrinsic limitations of the environment. Small enough to verify aspects by separate hand calculations and assure applicable conservation laws are obeyed. Within scope and applicability. If you think that a model complex enough to be a stretch for LS-DYNA or Abaqus can be done accurately in a physics engine, I wouldn't be surprised, but you'd be wrong.

This is a tool far more suitable for the job the engine above tries to do, yet is still a stretch. Notice that in expert modeling of progressive collapse, even with the expertise and best tools, a far less ambitious type of model is generally attempted. Consider the extensive amount of empirical corroboration associated with simulation of even the smallest components discussed in that paper. How much empirical validation was done of the simulation you offered? I'll bet you don't know. I'll bet it was none.

Oh, it matches your expectations.


More serious simulation:

TSN Studios - Extreme Loading For Structures - YouTube (A.D.D. readers go to 2:00 min mark)
Stubbs Tower - Savannah Demolition - YouTube
AP Murrah Simulation - YouTube
Powerful Physics Engine - YouTube


I get the impression your notions of the physics of complex systems is informed by Grand Theft Auto. Well, here's an example of the physics you can get from game engines:

 

[ozeco41]

re: "Amateur Engineering" practice in progressive collapse analysis[W:222, 344. 1463]

... you know, stuff like that. And you do know, making you the "choir"; what I think is self-evident will very likely be denied by the "infidel."

It's only a duet at present - with some occasional complementary counterpoint from one of the "infidel"

..plus several playing off a different score..

...and apparently oblivious to it.

...My argument terminates at the point where I'm asked to prove these principles can or do apply in the real collapses....

That is where I take over with the applied physics and the "can" part. The "do" part suffers slightly from pedantic adherence to the principles of the "scientific method" and the potential for falsification of any hypothesis no matter how close to certain it may be.

... Proofs are rarely available, so something is better than nothing.

Those are the two extremes. Remembering that "best available hypothesis" is as good as you get with sci. method - even if it is as close to dead set certain as any "reasonable person" would want.

(Deliberate use of legal terminology :3oops: - there are advantages of using para-legal process because the word "proof" is allowed - even though it is no stronger than the sci. method equivalent. )

 

[Kat Dorman]

re: "Amateur Engineering" practice in progressive collapse analysis[W:222, 344. 1463]

In a nutshell, game physics is rigid body physics. You'll note, regarding both of the simulations KokomoJojo posted:

- there is zero deformation of any member
- all failure is fracture
- fracture occurs in arbitrary locations on columns

Those are not the properties of steel.

It's utterly useless, except to look realistic enough in a game to make teenagers froth. Engineers don't use those tools for those purposes, for good reason.

 

[Kat Dorman]

re: "Amateur Engineering" practice in progressive collapse analysis[W:222, 344. 1463]

I have lots of friends

A precise and credible answer, eh psikeyhackr? Did you 'like' it because it panders to your bias? Because you seemed skeptical in your response, as you should be.

 

[KokomoJojo]

re: "Amateur Engineering" practice in progressive collapse analysis[W:222, 344. 1463]

In a nutshell, game physics is rigid body physics. You'll note, regarding both of the simulations KokomoJojo posted:

- there is zero deformation of any member
- all failure is fracture
- fracture occurs in arbitrary locations on columns

Those are not the properties of steel.

It's utterly useless, except to look realistic enough in a game to make teenagers froth. Engineers don't use those tools for those purposes, for good reason.

aw come on, you give us a one column zinger and admit its not good, and I agree, and when I ask you to give me an example, any example of a structure consisting of multi interconnected columns that has asymmetrical damage that descends in a nice symmetrical manner like the wtc you simply go silent or write books about everything other than what I ask.

 

[KokomoJojo]

re: "Amateur Engineering" practice in progressive collapse analysis[W:222, 344. 1463]

A precise and credible answer, eh psikeyhackr? Did you 'like' it because it panders to your bias? Because you seemed skeptical in your response, as you should be.

but I am sure that everyone is waiting for your:

example of a structure consisting of multi interconnected columns that has asymmetrical damage that descends in a nice symmetrical manner like the wtc

 

[KokomoJojo]

re: "Amateur Engineering" practice in progressive collapse analysis[W:222, 344. 1463]

In a nutshell, game physics is rigid body physics.

heh it has more validity than what you put up!

 

[Kat Dorman]

re: "Amateur Engineering" practice in progressive collapse analysis[W:222, 344. 1463]

aw come on, you give us a one column zinger and admit its not good, and I agree...

Mine are simple systems well within the capabilities of the environment in which they were simulated. It is useful as an instructional aid for basic concepts, though you obviously need far more remedial work than these are capable of providing. There are not a showy piece of useless graphics like what you posted, with obviously unphysical characteristics visible at a glance.

...go silent...

Does it look like I'm silent? I comment point-by-point on the majority of what you say. The reverse is not true. Shall I collect all the points you've ignored to this stage and lay them out for all to see? Don't go there. Bricks, glass houses.

...or write books about everything other than what I ask.

Am I your ****ing slave? I asked you to look at a video and you couldn't be bothered. Again, glass houses.

 

[Kat Dorman]

re: "Amateur Engineering" practice in progressive collapse analysis[W:222, 344. 1463]

heh it has more validity than what you put up!

The reason I "write books" is that I provide substantial justifications for most of my claims, including references. Your sole method of debating consists of one-liner claims like this, unsubstantiated in ANY way.

 

[ozeco41]

re: "Amateur Engineering" practice in progressive collapse analysis[W:222, 344. 1463]

...It's utterly useless,..... Engineers don't use those tools for those purposes, for good reason.

True.

PLUS for explaining the Twin Towers collapses there are only two critical stages. And you either don't need or cannot use the tools. However you define the boundary between them the two stages are:

1) "Initiation" which was a cascade failure and too complex, too much data not available for any tool to be used.

2) "progression" AKA (completion of) global collapse. Which is so simple that tools are not needed.

CD not needed for "2)" - and for "1)" cannot be definitively "proved" by technical methods that no CD was needed.

No need for professional engineering purposes to know the details of the "cascade" - knowing it was a "cascade" is enough for professional purposes. And it is a 4D multi factor multi path cascade unlike (say) electricity grid cascade failures which are either (single) linear or a definable branching of several linear paths. Where the structural failure at any point is multi factor analogue whilst the electricity grid case is sequential binary fails at each point. Orders of higher complexity for WTC initiation. And I haven't seen that point of distinction stated elsewhere....we see so much assumptions of a situation far simpler than it was in reality.

Hence my preferred explanation "It was a cascade and no one has made a viable hypothesis for CD". A lot easier innit? :mrgreen:

 

[Kat Dorman]

re: "Amateur Engineering" practice in progressive collapse analysis[W:222, 344. 1463]

heh it has more validity than what you put up!

In fact, this statement is patently false. Everything I've posted obeys laws of physics because I kept things reasonable for a GAME engine, and took pains to verify validity through all sanity checks possible. What you posted is a mish-mash of unphysical garbage.

You're confusing complexity with accuracy, and value appearance over substance. Mostly, you'll embrace whatever confirms your faith.

 

[Kat Dorman]

re: "Amateur Engineering" practice in progressive collapse analysis[W:222, 344. 1463]

Once again, the really important question is, how long shall I engage this nonsense?

 

[KokomoJojo]

re: "Amateur Engineering" practice in progressive collapse analysis[W:222, 344. 1463]

In fact, this statement is patently false. Everything I've posted obeys laws of physics because I kept things reasonable for a GAME engine, and took pains to verify validity through all sanity checks possible. What you posted is a mish-mash of unphysical garbage.

You're confusing complexity with accuracy, and value appearance over substance. Mostly, you'll embrace whatever confirms your faith.

and a lot of your work went right into the garbage. You continue to attack everything and anything to avoid producing:

example of a structure consisting of multi interconnected columns that has asymmetrical damage that descends in a nice symmetrical manner like the wtc

 

[Kat Dorman]

re: "Amateur Engineering" practice in progressive collapse analysis[W:222, 344. 1463]

Hence my preferred explanation "It was a cascade and no one has made a viable hypothesis for CD". A lot easier innit? :mrgreen:

It is. I've copied it so I can paste as needed.

 

[ozeco41]

re: "Amateur Engineering" practice in progressive collapse analysis[W:222, 344. 1463]

It is. I've copied it so I can paste as needed.

The usual deal for royalties??


BTW is "royalties" the term in USA?

 

[KokomoJojo]

re: "Amateur Engineering" practice in progressive collapse analysis[W:222, 344. 1463]

Once again, the really important question is, how long shall I engage this nonsense?

you already look pretty silly to have claimed you are an engineer and are incapable of responding in substance to simple problem I gave you,

provide an example of a structure consisting of multi interconnected columns that has asymmetrical damage that descends in a nice symmetrical manner like the wtc

so that cat is already out of the bag and the only way to save yourself now is to come up with something.

Face it I came up with "something" and despite your nit picking criticism you have have not produced anything close yet want to claim credit for accuracy. I will give you accuracy despite the fact you still fall far short of what I posted.

You have the option of course to prove everything you say by providing the example, or you can simply continue to dodge or do what most debunkers do when they are in a corner they cant get out of of. Put the SOB on ignore with a bluff that what you have should be gospel and the person who cornered you has nothing then have other debunkers quote me for you so you can respond by proxy. LOL But bluffs dont go very far.

The best however is simply to produce what is being asked since it is precisely on point and valid.

So what are you going to do?

 

[Kat Dorman]

re: "Amateur Engineering" practice in progressive collapse analysis[W:222, 344. 1463]

and a lot of your work went right into the garbage.

Which to say what? Be specific.

You continue to attack everything...

I attack ignorant nonsense and naive, faith based science.

...and anything to avoid producing:

example of a structure consisting of multi interconnected columns that has asymmetrical damage that descends in a nice symmetrical manner like the wtc

Aside from not being your bitch, where do you suppose such examples would be drawn from? Demolitions apply symmetric damage and are thus disqualified. You've provided two of the only four or five examples of buildings that have fallen over. Funny, none of them are steel framed, but hey, what's a little hypocrisy?

All the same, if I run across one, you'll be the first to know.

Now, quid pro quo: I'll ask you - like your were my ****ing handmaiden - find me ONE example of steel columns that fracture in the manner of that simulated crapola you hold in such high esteem. (oh, and while you're at it, debris that flies off under its own power :lamo )

 

[Kat Dorman]

re: "Amateur Engineering" practice in progressive collapse analysis[W:222, 344. 1463]

you already look pretty silly to have claimed you are an engineer and are incapable of responding in substance to simple problem I gave you,

provide an example of a structure consisting of multi interconnected columns that has asymmetrical damage that descends in a nice symmetrical manner like the wtc

You are equating engineering education and experience with me not being your step-n-fetch-it bitch?

Face it I came up with "something"...

:lamo

So what are you going to do?

Stop throwing good time after bad, for the moment.

 

[KokomoJojo]

re: "Amateur Engineering" practice in progressive collapse analysis[W:222, 344. 1463]

Hence my preferred explanation "It was a cascade and no one has made a viable hypothesis for CD". A lot easier innit? :mrgreen:

Implosions cause cascade failure.

No one has made a viable case for natural collapse.

and from the way you are talking you cant prove your case.

you know from a legal standpoint.

(oh and for the record, implosions in reference to demolition)

 

[KokomoJojo]

re: "Amateur Engineering" practice in progressive collapse analysis[W:222, 344. 1463]

You are equating engineering education and experience with me not being your step-n-fetch-it bitch?



:lamo


Stop throwing good time after bad, for the moment.

You desparately need it to give any credibility what so ever to your position however.

debunkers come out here and rooty toot all the time and one thing people have learned is that they NEVER produce a supportable claim for natural collapse. Ever notice that?

So whats it going to be? Everyone else (debunker parrots) simply runs.