tsig
a carbon based life-form
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- Nov 25, 2005
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- 39,049
The ball catches up with the goalposts and glides serenely thru them. I have special explosives in my boot.
Moderated Steel structures cannot globally collapse due to gravity alone
- Thread starter Heiwa
- Start date
The ball catches up with the goalposts and glides serenely thru them. I have special explosives in my boot.
You really tried to hit a ball full of cement? Don't blame me! Blame NIST and Bazant. Your foot (and leg) is supposed to be rigid.
Actually, no; firstly cement is a dry powder. I would expect an engineer to know the difference between cement, mortar, and concrete. Alternatively you might mean an air-set cement, however this would technically be a neat grout.
Turning to the specifics of your analogy, in engineering terms there are a number of pin and hinge joints all of which would have to be analysed against the forces arising from the collision/kick in order to arrive at a conclusion on their failure.
More importantly, however, an engineer would want to examine the relative strengths of the two different materials (viz, bone and concrete).
[sigh] ....... ruddy amateurs ......
Heiwa, would you be so kind as to comment on this following post?
Sigh... once again, for the truthers. And I'd love to see this question answered for a change.
How can such a floor...
... stop something like this...
Stupid
Thinker
- Joined
- Apr 27, 2008
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- 145
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whoa whoa WHOA, hold up! Heiwa's an engineer?!?! Holy monkey!
Judy Wood?
Heiwa is this guy, Andres Bjorkman. He makes Judy Who Would? look like a Nobel Prize winner.
Yeahh I would say that Judy Wood is more qualified to talk about building collapses than Mr. Bjorkman...strictly based on the education backgrounds. I was under the initial impression that Heiwa was an ME or perhaps even a CE. Nevertheless I find it hard to believe that any engineer, of any field, sane or not, would compare a football(or pizza boxes or cars) with the WTC Towers. Just...........baffling.
Heiwa, what do your colleauges say about your research?
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They are 100% behind me. No surprise really.
Who has suggested otherwise? Ever tried to kick a bag of cement? The paper bag is quite strong, you know. You don't have to wet the cement to get hurt.
Re pin and hinge joints you are just kicking an open door. But try when the door is closed!
whoa whoa WHOA, hold up! Heiwa's an engineer?!?! Holy monkey!
Judy Wood?
A long while back I quizzed Heiwa on the actual, real-world, out-on-the-sea engineering projects he had worked on. The only thing he came up with was a lifeboat davit welding project for a Mediterranean ferry.
I strongly suspect he is not an engineer at all.
Knowledge of the issues surrounding scaling is pretty much general knowledge really, for any person with a scientific background. Heiwa either lacks this or is simply pulling legs here.
Sword_Of_Truth
Penultimate Amazing
- Joined
- May 8, 2006
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- 11,494
I agree. He specifically claims to be a naval architect and marine engineer. But consider the following:
A thirty thousand ton mass of water dropped on either of the twin towers would completely destroy them.
A large mass of water plus a dash of acceleration makes for an incredibly destructive combination. This is the very first thing an engineering student would learn as he begins his specialization in marine engineering.
Every hear of a "tsunami", Hiewa?
MRC_Hans
Penultimate Amazing
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- Aug 28, 2002
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- 24,961
OK, let's say that. So one failure does not cause global collapse. Now, a second failure occurs. Load tranfers to the remaing structire. Now, a third failure occurs. Load transfers to the remaining structure. Etc....
Are you claiming that there will never come a point where the structure fails globally?
Hans
ElMondoHummus
0.25 short of being half-witted
ElMondoHummus
0.25 short of being half-witted
Even though you're already 12 posts in, if no one else has welcomed you to the forum yet: "Welcome!"
. And now to your point: Yes, even we non-engineer and non-architect folks here have figured out what you have said, just nowhere near the same level of detail. Thanks to the various engineers and architect trained posters who've helped us understand this; another such as you is always welcome here. But anyway, yes, it's true: So much depends on specific aspects of how a building was constructed that sweeping conclusions about failure behavior such as what Heiwa makes are unsupportable. It really doesn't help that his analogies are also getting sillier with each post.
Heiwa might be able to gain some headway if his thesis about how steel reacts in a collapse didn't contradict already established principles of steel failure, but unfortunately, this doesn't seem to bother him.
Anyway, thanks for participating. Chalk this up as yet another person who sees through the silliness.
Yes. You are just describing how to carry out structural damage analysis; you identify the first structural failure (e.g. due to fire or overload) and do a static structural analysis to see if there will be a second failure that further modifies the structural arrangement and the loads applied. Then you redo the static analysis with that case to identify the third failure, etc, etc. You establish a path of failures.
NIST never did that for WTC7. Evidence for that is that NIST agrees in the final 'final' report - see fig. 3-15 - that the structure above floor 16 is in 100% free fall for 2.25 seconds. The beauty with a structure in free fall is that gravity does not impose and loads at all on the structure! All gravity induced stresses and deformations in the structure becomes zero (0 !!) and no failures can take place anywhere.
Strangely enough NIST suggest the opposite and show three, four pictures to this effect, incl. parts flying around but the pictures are simply faked!!
The WTC7 structure was very simple - vertical columns carrying primary loads transmitted to them by horizontal (floor) beams carrying secondary loads.
A failure of a beam anywhere for any reason (fire!) will just cause the secondary load on it to drop down on the beam below ... and that's it. Further failures are arrested. The loads in the columns do not change at all.
A failure of a column for any reason (buckling due fire suggested by NIST) will just cause the primary load carried by it to be transferred to adjacent columns via the beams. Sudden simultaneous collapse of all columns resulting in free fall of structure above is not possible.
It is all explained at http://heiwaco.tripod.com/nist7.htm .
Heiwa
DavidJames
Penultimate Amazing
Sorry, Doc Brown had much more sense then Heiwa.