Review of Gravy's film at ABOVE TOP SECRET

[bynmdsue]

If "1 to 2 lb. shaped charges" took out the core columns,why did the cores remain standing longer than the rest?

 

[cmcaulif]

Stop trying to impress everyone with the integral BS. You know darn right well that the rule of thumb for Maximum shear stress for steel is .5 of ultimate tensile stress and the less conservative Von Mises stress for steel is .577 of ultimate tensile stress.

Are you trying to say that the shear stress for A36 steel is not in the vicinity of 21,000 psi?

psi stands in stead of pounds per square inch. a pound is in the units of force. You were using the energy of a TNT explosion, energy is in units of work, which is force times distance.

So if you use the shear capacity of steel in units of force per area, and try to compare with the energy of TNT, in units of work, it wont be dimensionally homogeneous, in other words, it doesn't mean anything.

If you want to use energy methods, you have to use the shear energy, compared to the TNT energy.

 

[Newtons Bit]

Stop trying to baffle everyone with the integral BS. You know darn right well that the rule of thumb is that Maximum shear stress is .5 of ultimate tensile stress for steel and the less conservative Von Mises stress is .577 of ultimate tensile stress.

Are you trying to say that the maximum shear stress of A36 steel is not in the vicinity of 21,000 psi?

Okay, let's analyze a couple of things here. The maximum shear stress is typically taken as 0.6*Fy (Fy = yield stress) in modern codes. Older codes allowed as much as 0.8, as this was backed up by testing. More modern research showed that there was a larger variance in shear capacity of steel, this led to the allowable shear capacity being lowered to increase the confidence in shear. In layman's terms, they lowered the allowable because a small percentage of correctly[/b designed, correctly manufactured and correctly constructed (by code) steel members were still failing.

You also say "ultimate tensile stress". This is not the yield stress of 36ksi. Ultimate stress, or tensile stress of A36 steel is at a minimum 58ksi (for very large sections) and can be as high as 80ksi. If you were a professional who used these terms since you graduated college, wouldn't mess them up.


And I'm saying: you're full of ****. Please elaborate on how in*lb = lb/in.

 

[R.Mackey]

I wish I could change units like that when doing an assignment, save time, better grades, it sounds like a much easier system for everyone involved.

The problem isn't units, it's more fundamental than that.

realcddeal is attempting to calculate shear strength. He does this by estimating the shear strength per unit cross-section, starting with an estimate of shear strength in PSI (lb / in²) and then multiplying by the thickness (PSI x in = lb in / in² = lb in).

of course, it just isn't anywhere near that simple.

ETA: Actually, on review, he's not even estimating strength. He's dividing total explosive energy by cross-section, comparing that to a hypothetical calculation as above, and then assuming the result is so large that he doesn't have to compute it. Neither calculation is valid, of course.

 

[Tony Szamboti]

I wish I could change units like that when doing an assignment, save time, better grades, it sounds like a much easier system for everyone involved.

Okay, I'll mollify you.

A one pound charge of C-4 has 17.3 x 10e6 inch pounds of energy.

It takes 20,772 inch pounds of energy to shear through one sq. inch of A36 steel.

17.3 x 10e6 inch pounds/(20,772 inch pounds/sq. inch) = 832.8 sq. inches

This shows that there is enough energy available at 100% efficiency (not saying it is) to shear through 832.8 sq. inches of A36 steel.

This is for just a one pound charge. Two pounds will do 1665.6 sq. inches.

If you want to quibble about efficiency now you are going to have to show something real because the numbers are overwhelming.

 

[beachnut]

I would definitely not say I am preaching to an extremely dull-witted and uncritical choir here and I have been spending a good bit of my time here lately.

As for Mark I have shown that the premise of his video, claiming that those who believe the buildings were taken down via controlled demolition think there needed to be a huge amount of explosives, is simply wrong.

A controlled demolition of the twin towers would have used a minimum amount of explosives. As I have shown here, one to two pound charges were plenty capable of taking out the core columns. All that was necessary to bring those buildings down was to take out a majority of the core columns.

It wouldn't have been anything like the huge charges that Mark shows on his video, and since the charges would have been on the core columns they would have been well inside the perimeter, keeping the demolition charges from being visible, although a few did escape the perimeter. The collapse of the buildings would have masked the audible sounds of these relatively small charges.

For now I think the written word is the appropriate way to debate this topic. Maybe when it is all over, if you want, I will stop by your show.

You are so challenged on research. Mark's video is very good. You have just shown you do not understand CD. Gravity is the prime mover on CD as it was the only mover on 9/11 after the failure due to impact and fire. Mark makes it clear to me that the idiots for 9/11 truth think the explosives were used to dustify the WTC concrete. Dim witted 9/11 truth movement dolts are all into the crap of CD without a single piece of evidence.

It is clear, when you see Mark's example of the 5 pounds of TNT, there were zero explosives on 9/11. Further, the kind of CD that uses small amount of explosives have to be on the steel beam, and includes extra charges to cut the steel. Such an effort would have been discovered by tenants who do not want their walls cut! What kind of engineer would believer 9/11 truth junk? Hello?

You may not like the video because it makes sense, not like the tripe you put in your paper at the 9/11 truth journal, peer reviewed by total idiots when it comes to 9/11 topics. Sorry, but at my engineering school they thought you should be rational not stupid.

The video is an excellent tool to get a good idea about what real explosives do.

 

[Tony Szamboti]

Okay, let's analyze a couple of things here. The maximum shear stress is typically taken as 0.6*Fy (Fy = yield stress) in modern codes. Older codes allowed as much as 0.8, as this was backed up by testing. More modern research showed that there was a larger variance in shear capacity of steel, this led to the allowable shear capacity being lowered to increase the confidence in shear. In layman's terms, they lowered the allowable because a small percentage of correctly[/b designed, correctly manufactured and correctly constructed (by code) steel members were still failing.

You also say "ultimate tensile stress". This is not the yield stress of 36ksi. Ultimate stress, or tensile stress of A36 steel is at a minimum 58ksi (for very large sections) and can be as high as 80ksi. If you were a professional who used these terms since you graduated college, wouldn't mess them up.



And I'm saying: you're full of ****. Please elaborate on how in*lb = lb/in.

I did mean to say tensile yield stress. Which for A36 is 36,000 psi. I will correct that but it does not change anything.

The point is that small charges could take out those core columns and you know that. If you don't you should.

Again I am asking you if you are trying to claim that the shear yield stress for A36 is not in the vicinity of 21,000 psi?

If we use a maximum ultimate tensile strength of 80 ksi which would give an absolute maximum shear stress of 46.16 ksi then the one pound charge is still capable of taking out a 375 sq. inch cross section. A two pound charge then does 750 sq. inches. These are way beyond the 120 sq. inch crosss section wide flange you mentioned.

 

[Tony Szamboti]

If "1 to 2 lb. shaped charges" took out the core columns,why did the cores remain standing longer than the rest?

I believe that only the outer core columns needed to go to bring down the towers. Much of the inner columns in rows 600, 700, 800, and 900 would have been dragged down by the outer columns at the upper levels were they were weaker. Lower levels remained due to their ability to resist being dragged down by their beam connections to the outer columns.

 

[Tony Szamboti]

You are so challenged on research. Mark's video is very good. You have just shown you do not understand CD. Gravity is the prime mover on CD as it was the only mover on 9/11 after the failure due to impact and fire. Mark makes it clear to me that the idiots for 9/11 truth think the explosives were used to dustify the WTC concrete. Dim witted 9/11 truth movement dolts are all into the crap of CD without a single piece of evidence.

It is clear, when you see Mark's example of the 5 pounds of TNT, there were zero explosives on 9/11. Further, the kind of CD that uses small amount of explosives have to be on the steel beam, and includes extra charges to cut the steel. Such an effort would have been discovered by tenants who do not want their walls cut! What kind of engineer would believer 9/11 truth junk? Hello?

You may not like the video because it makes sense, not like the tripe you put in your paper at the 9/11 truth journal, peer reviewed by total idiots when it comes to 9/11 topics. Sorry, but at my engineering school they thought you should be rational not stupid.

The video is an excellent tool to get a good idea about what real explosives do.

You are sure that the planting of charges would be discovered. What makes you so sure?

 

[cmcaulif]

Okay, I'll mollify you.

A one pound charge of C-4 has 17.3 x 10e6 inch pounds of energy.

It takes 20,772 inch pounds of energy to shear through one sq. inch of A36 steel.

17.3 x 10e6 inch pounds/(20,772 inch pounds/sq. inch) = 832.8 sq. inches

This shows that there is enough energy available at 100% efficiency (not saying it is) to shear through 832.8 sq. inches of A36 steel.

This is for just a one pound charge. Two pounds will do 1665.6 sq. inches.

If you want to quibble about efficiency now you are going to have to show something real because the numbers are overwhelming.

Wait, was that a joke? I just made a tongue in cheek remark about how you don't understand units, and you reply with a display of your misunderstanding of units.

21000 pounds per square inch is the approximate shear capacity of A36 by the code.

If you want to calculate the energy needed to shear a given cross section, it is dependent on the shear force, shear modulus, and the section geometry, as NB showed.

 

[beachnut]

Not you again!

Mark's video is very nice and I enjoyed the music but its premise is wrong.

The size of the charges on the core columns in the towers would not need to be large.

But tell all the people how close the charges have to be to the steel. Tell them how they have to remove all the insulation and place the charge; then tell them how the wires have to run. Then tell them how the shaping charges have to be placed to blow the columns the direction you want them to go. Yes, I know there are only a small about of explosives needed to bring down a building compared to the energy of gravity stored in the building. I know gravity is the primary energy in all CD. I know the charges have to be on the steel, unless you use massive amounts of explosives. I know there were zero explosives used to bring down the WTC on 9/11. You have made up false ideas without any evidence. You just make it up. So sad to have a few engineers in the whole world make up lies about 9/11 with NO evidence. You are in select few people with idiot ideas on 9/11, that is less than 0.00067 percent of all engineers. So few wrong. So sad. Pathetic.

When did the evil doers set the explosives up? How close does that little charge have to be? Why do most 9/11 truth movement people think there were lots of explosives? Why do you have so many errors in you paper?

Then pleas answer the question why section of the core stood well after most the mass of the WTC left? Then try to correct your paper of errors before someone you know sees your work of woo.

If only you have a coherent story for this big CD plot; what does this remind me of Bigfoot or some other weird junk made up by real weird people?

 

[beachnut]

You are sure that the planting of charges would be discovered. What makes you so sure?

Okay, tell me how they were planted? Tell me where, and how much insulation was removed? How thick the insulation was? Where did they put the insulation after it was removed? Where they ran the wires? If you used radios, please tell me the frequency they used; please do not use 2.4 Ghz? Next, since there were no blast sounds or effects found during or after 9/11; what new stealth explosives were used? Why were there no blast effects? What was there zero evidence of cutter charges on the thousands and thousands of beams form the WTC which many independent investigators had access to?

Why did you leave out all the fancy ways of setting up explosives in your incredibly error ridden paper?

Do not forget to tell us all how the explosives were set off? How? Good luck tony.

 

[Tony Szamboti]

Wait, was that a joke? I just made a tongue in cheek remark about how you don't understand units, and you reply with a display of your misunderstanding of units.

21000 pounds per square inch is the approximate shear capacity of A36 by the code.

If you want to calculate the energy needed to shear a given cross section, it is dependent on the shear force, shear modulus, and the section geometry, as NB showed.

You criticism can't even be called nit picking. Are you trying to tell me that that material won't start to move in shear at around 21,000 psi?

 

[Tony Szamboti]

Okay, tell me how they were planted? Tell me where, and how much insulation was removed? How thick the insulation was? Where did they put the insulation after it was removed? Where they ran the wires? If you used radios, please tell me the frequency they used; please do not use 2.4 Ghz? Next, since there were no blast sounds or effects found during or after 9/11; what new stealth explosives were used? Why were there no blast effects? What was there zero evidence of cutter charges on the thousands and thousands of beams form the WTC which many independent investigators had access to?

Why did you leave out all the fancy ways of setting up explosives in your incredibly error ridden paper?

Do not forget to tell us all how the explosives were set off? How? Good luck tony.

Only someone like you, with a one track mind, would dismiss what I am saying concerning the erroneous premise in Mark Roberts video. The reality is that small charges were used to bring down those towers and they would not be very visible being on the core columns nor very audible during the collapse which was a rolling wave due to being taken down every three stories.

Gravity then did the rest of the work, like pulverization, due to tremendous dynamic loads, only after these columns were cut loose.

Goodnight and good luck to you too.

 

[Newtons Bit]

You criticism can't even be called nit picking. Are you trying to tell me that that material won't start to move in shear at around 21,000 psi?

Your units don't match. You cannot compare lb/in and lb*in and say one is bigger than the other, they're completely different things.

There now, is that big enough for you? You can't avoid text that big.

 

[cmcaulif]

You criticism can't even be called nit picking. Are you trying to tell me that that material won't start to move in shear at around 21,000 psi?

Pointing out that stress and energy are NOT interchangeable is nitpicking?

Of course the material will move in shear at around 21000 psi, however you have not proven that it will reach that stress. You can attack the problem in two ways, from load, or energy, but you cannot say that the STRESS at which the material slips in shear is the exact same number as the ENERGY that the cross section slips in shear.

Newtons Bit gave you the equation you need to calculate the shear energy, since you are using the energy of the explosion, you will need to use this equation for your calculation to mean anything.

 

[Newtons Bit]

It takes 20,772 inch pounds of energy to shear through one sq. inch of A36 steel.

No, it doesn't. It takes 20,772 pounds of force to shear through one square inch of A36 steel.

 

[Tony Szamboti]

Your units don't match. You cannot compare lb/in and lb*in and say one is bigger than the other, they're completely different things.

There now, is that big enough for you? You can't avoid text that big.

You apparently didn't look at the post where I showed the units properly to mollify your irrelevant nitpicking.

I have to say that you have a very nasty disposition there pal.

Don't forget that you are the one who threw the first snide remark as in "Oddly enough" and you were wrong. I don't think I need to increase the font here. You will get the message.

 

[beachnut]

Only someone like you, with a one track mind, would dismiss what I am saying concerning the erroneous premise in Mark Roberts video. The reality is that small charges were used to bring down those towers and they would not be very visible being on the core columns nor very audible during the collapse which was a rolling wave due to being taken down every three stories.

Goodnight and good luck to you too.

As expected you can not even tell me how they planted the explosives next to the steel. Zero evidence, no idea. This is 9/11 truth. Good job tony man.

Tony, Marks Video shows the blast effects of a small charge; you can not even tell me how they were planted in the WTC. Where did they put the insulation? How did they get the explosives to be silent; RDX makes a sound that would be recorded for miles! Why are you unable to produce any sound. Please do not post the fraud sound videos.

Run away

 

[Newtons Bit]

You apparently didn't look at the post where I showed the units to mollify your nitpicking.

You mean where you showed lb*in = lb?