Working on the certainty that you will ignore my question, let's try this approach. Your model assumes a mass of x for the perimeter panels. The engineers have repeatedly explained that this amount is a tiny fraction of the total mass of the building. You conduct two tests, first increasing the mass of the panels by 20% and then decreasing it by 20%. You get the same results in both cases. Why do you require greater precision? Please explain.
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Hardfire: Physics of 9/11
- Thread starter R.Mackey
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Working on the certainty that you will ignore my question, let's try this approach. Your model assumes a mass of x for the perimeter panels. The engineers have repeatedly explained that this amount is a tiny fraction of the total mass of the building. You conduct two tests, first increasing the mass of the panels by 20% and then decreasing it by 20%. You get the same results in both cases. Why do you require greater precision? Please explain.
I haven't said it should make a huge difference. I've said I prefer to use actual rather than estimated data. If you can't handle that, fine.
As I've also said, if I could get data on where chairs were placed, in principle I'd add that too. Would that make a difference to the 'collapse' time ? No, but it would be more correct data.
You don't have the data. When you do, please let me know.
If I get hold of it, I'll make it known.
Stop dancing. Nobody thinks that precise data will make a "huge" difference. I keep asking if it would make ANY difference. You seem unable to figure out the difference between "correct" and "significant." Why would knowing where the chairs were placed be SIGNIFICANT?
Please read my previous question again. If you get the same result after increasing the estimate as you get after decreasing it, what is the necessity for precise data?
You appear to be unable to read:
Would it make ANY difference ? Of course, minimal maybe, but a difference indeed.
Principles.
If you get hold of more accurate data, please let me know.
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rwguinn
Penultimate Amazing
Comedy Gold.
You quote "principles", yet are using an approximation (all FE equations are approximations--hell-all analysis mathematics of any kind is approximate)--and a linear approximation at that, for a complex, highly non-linear event.
I read very well, thank you. You are blowing smoke and failing miserably.
WHAT difference would it make? If the result is the same after increasing your estimate by 20% and decreasing it by 20%, we can all see that your insistence on precise numbers is a sham.
There are no principles involved. You are attempting to con us.
You really are unable to read. I'm not insisting on precise numbers at all. I'm asking if they are available, as I would prefer to use them over the use of estimates. Clearly they are not available.
If you get hold of said data, please let me know.
Your insults can't disguise the fact that you have been caught. WHY do you prefer precise numbers over estimates if the result is the same? If you can read, you will address the question I'm asking. What is your "preference" based on? WHAT DIFFERENCE DOES IT MAKE?
Newtons Bit
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WTF are you trying to do here? Just annoy him and waste his time?
It is entirely logical to use the actual accurate information if it exists.
WTF are you trying to do here? Just annoy him and waste his time?
It is entirely logical to use the actual accurate information if it exists.
Of course it's logical to use accurate information if it exists. Who thinks otherwise? Psikeyhackr went on and on about the precise weight of the permiter panels. I don't think he has any idea why he wants to know the precise weight. Femr2 is playing the same game. Look, you're an engineer and I'm not. All I'm saying is that close estimates are often good enough. Let's suppose that some mass unknown to us is, to take an arbitrary number, 100. If one of our models assumes a mass of 120, another assumes a mass of 80, and the results are the same in both cases, WHAT DIFFERENCE DOES IT MAKE THAT WE DIDN'T USE THE PRECISE NUMBER 100?
psikeyhackr
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ROFL
It's gone from EXACT to perfect even though I showed here:
http://www.internationalskeptics.com/forums/showpost.php?p=4681054&postcount=1256
how much changes in the weight of the panels could make in the impact area. No one has explained what is wrong with my grade school math. But I have never seen anyone else say much about the weight distribution and the energy of that oscillation.
So if any OFFICIAL SOURCE ever says that mass distribution is important enough to affect the results a lot of people are going to look AWFULLY STUPID for the last Seven Years. The wall panels held up 50% of the weight of the building but we aren't told the number and weights of the panels. TOTALLY RIDICULOUS!!!
All of the shrinks and psychologists will have to be put on 911 Psychosis relief. How will historians explain this is 100 years. Nation that put men on Moon can't deal with mass distribution of skyscrapers. NASA scientist Mackey stumped.
psik
.
ROFL
It's gone from EXACT to perfect even though I showed here:
http://www.internationalskeptics.com/forums/showpost.php?p=4681054&postcount=1256
how much changes in the weight of the panels could make in the impact area. No one has explained what is wrong with my grade school math. But I have never seen anyone else say much about the weight distribution and the energy of that oscillation.
So if any OFFICIAL SOURCE ever says that mass distribution is important enough to affect the results a lot of people are going to look AWFULLY STUPID for the last Seven Years. The wall panels held up 50% of the weight of the building but we aren't told the number and weights of the panels. TOTALLY RIDICULOUS!!!
All of the shrinks and psychologists will have to be put on 911 Psychosis relief. How will historians explain this is 100 years. Nation that put men on Moon can't deal with mass distribution of skyscrapers. NASA scientist Mackey stumped.
psik
The same post over and over. Mackey isn't REALLY stumped. You haven't understood a word the engineers have written. You refer us to your post #1256, but you ignore post #1265. Why?
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Furcifer
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Why don't you tell us how the known frequency of oscillation will be affected by the weight distribution of the panels or the core for that matter. Then I'll explain to you why the mass and velocity of the plane is more important.
lol, your grade school math is fine, it's your feeble attempts at applying it that suck. Could you please show us how you did a linear interpolation to get the displacement of a transient wave in a non homogeneous structure?
(seriously you should write this stuff down and send it to your local University physics or math departments. Use the title "LePsikey Transforms" or "Psikeyier Analysis" your choice although I am most fond of the first)
LOL, I want to put you on ignore but your arrogance is only out shone by your ignorance, and that sir is worth the price of admission!
psikeyhackr
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I have seen Lon Waters' site before and exchanged emails with him.
I don't see anything there about perimeter panels that isn't in the NCSTAR1 report. Even if it were possible to compute the weight of the panels that wouldn't tell us the numbers of each type.
So what is your problem with the NIST coming up with 24 numbers. What were they paid $20,000,000 for? Wouldn't 24 numbers fit in those 10,000 pages?
psik
Tony Szamboti
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The only information I have found for at least a semblance of the locations of the various grades of perimeter panels is in one of the Engineering News Record articles from the late 1960s. In case you haven't see it here is a link to it.
http://911research.wtc7.net/mirrors/guardian2/wtc/eng-news-record.htm
However, there isn't any information on wall thicknesses of the perimeter columns over the height of the towers and the NIST has only released that information for the core columns. Since the exterior configuration of the perimeter columns did not change from the 110th to the 9th floor (where it transitioned into the trees) you could approximate the wall thicknesses knowing the factor of safety of the perimeter was 5.00 to 1 minimum for gravity loads only and the mass above using Gregory Urich's mass analysis, which seems to be a reasonable estimate of the actual mass using available data.
http://www.journalof911studies.com/volume/200703/GUrich/MassAndPeWtc.pdf
Tony Szamboti
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One other important point, that you will find in the Engineering News Record, is that all of the columns (both core and perimeter) of a given story were kept at the same unit stress to eliminate floor warpage.
Tony Szamboti
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The NIST SAP2000 data that Lon Waters went through and categorized only had full information on the core columns.
It is peculiar that the NIST has not released the information on the locations of the various grades of perimeter columns and the wall thicknesses at those locations. It is also peculiar that they have not released the central core horizontal beam sizes over the height of the towers.
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boloboffin
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It is peculiar to me that by showing Bazant's limiting example to have actually not happened, you think you have shown that his limiting example is not true. It is peculiar to me that you think you can measure something so precise as a 0.01 f/s gain in velocity over .6 seconds, but you can't pull the acceleration numbers out of that and see that your idiosyncratic goalpost of "deceleration" probably happened right there.
AZCat
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"Unit stress"? What do you mean? Stress is already per unit area.
Furcifer
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Given the number of pre fabricators and the scale of the project I'm not surprised the actual grades and plate thickness of every column was not recorded. Even if they were recorded, why would they be kept for 30 years by all 15 fabricators? Without NIST having coupons from every column they wouldn't know either. As for the mass, the only one who would have been concerned with that would have been the crane operator.