Behavior of steel framed structures under fire conditions.

The debunking on this thread is deafening. Could you stop please? I can't keep up.

Originally posted by Griff
Valhall.

Do you have that information about eyewitnesses experiencing explosions and fires on the mechanical floors anymore? I just started a database (finally) of all the things. Thanks in advance.

Hi Griff,

I think these threads where I collected testimony and eye witness accounts, along with notes from radio transmissions are what you are referring to, right? If not, let me know and I'll keep looking.

www.abovetopsecret.com...
www.abovetopsecret.com...
www.abovetopsecret.com...
www.abovetopsecret.com...

[edit on 8-17-2007 by Valhall]

The WTC steel was tested and perfomed very well against high heat fire, thats why Kevin Ryan lost his job at UL, he was concerned about it and made and issue of it. Somebody didn't like that so they got rid of him.

Also ALL the South Tower steel failing in 56 minutes from impact in a total global collapse, thats just impossible.

As for people saying the impact did it, remember the plane was Almunium.

It's like taking a pop can and hurling it a building I beam, nothing happens to the I beam.

Originally posted by Blue_Jay33

As for people saying the impact did it, remember the plane was Almunium.

It's like taking a pop can and hurling it a building I beam, nothing happens to the I beam.

The plane is made out of "Aluminum", not aluminum foil or types of aluminum never meant to be used for aviation. The strength of aluminum varies differently. Could be soft or hard.

Did you know that our M113 APC military vehicle is made out of aluminum that has the same strength as steel? Surprised?

Originally posted by Valhall
Hi Griff,

I think these threads where I collected testimony and eye witness accounts, along with notes from radio transmissions are what you are referring to, right? If not, let me know and I'll keep looking.

www.abovetopsecret.com...
www.abovetopsecret.com...
www.abovetopsecret.com...
www.abovetopsecret.com...

[edit on 8-17-2007 by Valhall]

Yes. Thanks for doing the work and posting them again. Cheers.

Originally posted by deltaboy
Did you know that our M113 APC military vehicle is made out of aluminum that has the same strength as steel? Surprised?

Not surprised at all. Could you give me the basics of what is in the aluminum? I'm just curious. Thanks.

Originally posted by Griff

Not surprised at all. Could you give me the basics of what is in the aluminum? I'm just curious. Thanks.

www.fas.org...

The M113 APC was the first modern "battle taxi"; developed to transport infantry forces on the mechanized battlefield. It is fitted with a 2 stroke six cylinder Detroit diesel providing power through a 3 speed automatic gearbox and steering differential. The main armament is a single .50 Cal heavy barrel machine gun, and the secondary armament is a single .30 Cal machine gun. The M113 is built of aircraft quality aluminum which allows it to possess some of the same strengths as steel at a much lighter weight. This distinct weight advantage allows the M113 to utilize a relatively small engine to power the vehicle, as well as carry a large payload cross-country. The vehicle is capable of "swimming" bodies of water.

www.aluminum.org...

Report #476, "New Materials for Next Generation Aircraft"). Structural components of current United States Navy aircraft are made of fabricated wrought aluminum (forged, machined, and assembled parts). There are efforts underway to persuade the Navy to adopt aluminum casting technology which offers lower manufacturing cost, the ability to form complex shapes, and the flexibility to incorporate innovative design concepts.

Aircraft manufacturers use high-strength alloys (principally alloy 7075) to strengthen aluminum aircraft structures. Alloy 7075 has zinc and copper added for ultimate strength, but because of the copper it is very difficult to weld. It anodizes beautifully. 7075 has the best machinability and results in the finest finish.

www.suppliersonline.com...

Chemistry Data : [top]


Aluminum Balance
Chromium 0.18 - 0.28
Copper 1.2 - 2
Iron 0.5 max
Magnesium 2.1 - 2.9
Manganese 0.3 max
Remainder Each 0.05 max
Remainder Total 0.15 max
Silicon 0.4 max
Titanium 0.2 max
Zinc 5.1 - 6.1



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Principal Design Features The 7075 alloy is capable of high strength as developed by heat treating. It also has excellent properties at low temperatures.

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Applications Commonly used in the manufacture of aircraft and other aerospace applications not requiring the corrosion resistance of Clad 7075.

As you can see we are not dealing with aluminum that you use to cook food in the oven.

Here is very interesting video on this subject that clearly shows the truth:

uk.youtube.com...

Originally posted by deltaboy
As you can see we are not dealing with aluminum that you use to cook food in the oven.

Thanks for the chemistry lesson deltaboy. BTW, I was aware that it was a composite aluminum and not a soda pop can. I was just curious when you said as strong as steel.

They said as strong as some properties of steel. I'd bet not all. But, I'm not trying to argue with you.

Originally posted by Griff
I was just curious when you said as strong as steel.

They said as strong as some properties of steel. I'd bet not all. But, I'm not trying to argue with you.

You're right according to the figures I'm seeing.

I found this: www.alcoa.com...

They give a figure of 21 ksi or 145 MPa for alloy 7075's maximum yield strength. I'm finding about 36 ksi or 248 MPa for just mild steel up to the A569 standard.

Pretty impressive for aluminum I guess but it's still between only one-half and two-thirds as strong as a very commonplace kind of steel (maybe the most common form?).


Not to mention the fact that, with such thin aluminum against such thick steel, even if the aluminum was as strong as the steel, it would still be ripped to shreds just because of its light size.

[edit on 17-8-2007 by bsbray11]

For those of you living in Tornado areas of the country you know that simple 2"X4"'s can be thrown through severall feet of reinforced cement without even spintering. I bet your aluminum plane travelling at speeds twice that which the tornado throws things out can do a lot of damage to steel I-beams!

Blades of grass have been know to be imbedded as much as 2 inches into the sides of house. How is that for damaging!!!!!

[edit on 17-8-2007 by traderonwallst]

Originally posted by traderonwallst
For those of you living in Tornado areas of the country you know that simple 2"X4"'s can be thrown through severall feet of reinforced cement without even spintering.

That's a new one to me. Does anyone have any examples they can share (besides hearsay)?


It doesn't matter either way, because we know how many columns were knocked out. So we know how much damage the planes did. It's nothing really to have to speculate about.

I heard of such things happening, but never experienced tornadoes so I never try to learn about it.

I looked up some info about it...

www.insulatingconcretehomes.com...

Insulating Concrete Wall

The 4' x 4'6" insulating concrete wall test panel was filled with 3000 psi concrete and a #4 rebar at 24" o.c. vertically and #4 rebar at top and bottom horizontally. A 1/4" thick EIFS stucco was applied directly to the wall.

The 15-pound wood stud was fired at a speed of 103.8 mph and in a second test at 100.2 mph.

The wood stud broke and splinted into pieces after penetrating the foam but did no observable damage to the concrete in the insulating concrete wall.




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Wood Frame Wall

A 2 x 4 wood frame wall with 3/4-inch plywood sheathing and a 4-inch brick veneer was tested by firing a 15-pound wood stud at 69.4 mph.

Even at this slower speed, the wood stud perforated through the entire wall with little damage to the wood stud (missile).




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Steel Frame Wall

A 2 x 4 steel frame wall covered with 1-inch of foam insulation and an EIFS stucco system was also tested.

A 15-pound wood stud was fired at only 50.9 mph and went through the wall completely with no damage to the wood stud.

Wood penetrating steel? Wow...

It said it was steel framed, with foam and stucco or whatever else. So just a steel "skeleton" for a wall. It must have missed the steel completely. Either that, or the steel wasn't secured to the rest of the frame and just came out of place.

Steel is stronger than concrete, and the concrete obliterated the wood, like I was thinking it should. A 2x4 isn't going to be sent through the concrete in reinforced concrete at storm speeds, let alone steel. It would have to at least miss the steel, and bust the concrete all to hell.

I would like to point out as a Professional Engineer that the integrity of a steel structure obviously IS affected by high temperatures, it becomes easier to deform as it melts. Think of bending a decent gauge piece of metal, you need to heat it, this allows it to be bent. Now think of all the diagonal beams in a skyscraper with a vertical load acting on them. It is so obvious what is going to happen (they bend). Any deformation in the structure redirects the load, it is very easy from there to see that failures can and will occur due to excessive loading on other parts of the structure.
I would like to point out that I don't really care exactly why the twin towers collapsed, and I don't buy into some of these theories about what 'really' happened. All I care about is that loads of people were killed. And the opening post is laughable stating that metal brought to it's melting point is as strong as at ambient.

Originally posted by CarlosG
I would like to point out as a Professional Engineer that the integrity of a steel structure obviously IS affected by high temperatures, it becomes easier to deform as it melts.

I will not contest that you are a PE. What type may I ask? Your first sentence has one little flaw. The steel didn't melt.

Think of bending a decent gauge piece of metal, you need to heat it, this allows it to be bent. Now think of all the diagonal beams in a skyscraper with a vertical load acting on them. It is so obvious what is going to happen (they bend). Any deformation in the structure redirects the load, it is very easy from there to see that failures can and will occur due to excessive loading on other parts of the structure.

Very true. Can you calculate this added P-delta affect for us to show us? I would, but without knowing the members, it's difficult. Can you also show us the calculations of how the floor trusses (diagonal beams) can pull inward on the exterior columns allowing them to shear in not one place but two places at the same time? I'm not asking in jest. I'm really curious.

I would like to point out that I don't really care exactly why the twin towers collapsed, and I don't buy into some of these theories about what 'really' happened. All I care about is that loads of people were killed.

That is your poragative. Why post here then?

And the opening post is laughable stating that metal brought to it's melting point is as strong as at ambient.

Laughable is that you did not read anything I posted. It is obvious that you have not read it or you wouldn't have posted this. Good day to you. If you can answer my questions, I'd be greatful.

Originally posted by CarlosG
I would like to point out as a Professional Engineer that the integrity of a steel structure obviously IS affected by high temperatures, it becomes easier to deform as it melts.

o_O

And the opening post is laughable stating that metal brought to it's melting point is as strong as at ambient.

I can't find that statement. What opening post are you reading?

Any deformation in the structure redirects the load, it is very easy from there to see that failures can and will occur due to excessive loading on other parts of the structure.

Oh my gersh - you spent so little time reading the original poster's posts, and the referenced report, that you don't even realize that your argument is exactly what the reference paper states.

LMAO! Thanks for putting your P.E. stamp on the findings.

Wow Valhall.

I'm only about 4 or 5 pages into the first link you provided. Nice work in compiling all that. I'm surprised no one posted anything. I'm also surprised I missed most of it. It's a long read and I hope to read it all but you would think some people would chime in.

One interesting story off the top of my head was the person stating the bridge explosion and collapse before both towers collapsed. If I could give you my WATS for the next year, you'd deserve them.

I encourage everyone to read what Valhall has compiled. Thanks.

Originally posted by traderonwallst
If you want to learn more about steel try this web page:

www.key-to-steel.com...

Thanks for this link. I can use this for work. I realized I hadn't mentioned it. Thanks again.