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Thread: Any minute now it will collapse into it's own footprint, yup, any minute.

  1. #11
    Registered User PeoplesElbow's Avatar
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    For Gods sake, the fire did not have to melt the steel, heat exposure over a period of time weakens steel but that wasn't the only factor that lead into failure.

    Heat also causes expansion of steel, the steel beams expanded inducing thermal stresses that added to the stress placed on the steel from the weight of the building. The stresses were increased due to a significant number of the supports being taken out by an aircraft travelling 600 mph so there were less beams supporting the load.

    Here is a chart showing the strength of steel as it gets hotter, note this chart is only for 30 minutes exposure to the heat, it gets weaker the longer it is exposed to the heat. It is from MIL-HBK-5 which was the standard for aerospace metal properties, it has now been commercialized and called MMPDS, but you can find another source for this info if you like such as Marks Standard Handbook for Mechanical Engineering or probably some civil engineering reference (sorry not a civil engineer).

    Name:  Effect of temperature on the tensile ultimate strength and yield strength of low alloy steels.jpg
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    If what I say offends you then you really don't want to hear what I keep to myself.

  2. #12
    Quote Originally Posted by LightRoasted View Post
    Science is a funny thing isn't it? .
    To you, it apparently is. You certainly don't have even a basic grasp of it. Nobody anywhere, EVER, suggested that the structural steel in the towers "melted". What you and other conspiracy idiots conveniently chose to ignore is the effect of elevated temperatures, and time of exposure (heat soaking) on the yield strength of structural steel, and even more importantly, the buckling behavior of same. Other key factors are also important: What load path was actually heat affected? How extensively? What is the weight still bearing on the structure above the affected area and load path?
    Last edited by Gilligan; 06-14-2017 at 02:15 PM.
    "Cynicism is the smoke that rises from the ashes of burned out dreams."

  3. #13
    Quote Originally Posted by PeoplesElbow View Post
    For Gods sake, the fire did not have to melt the steel, heat exposure over a period of time weakens steel but that wasn't the only factor that lead into failure.

    Heat also causes expansion of steel, the steel beams expanded inducing thermal stresses that added to the stress placed on the steel from the weight of the building. The stresses were increased due to a significant number of the supports being taken out by an aircraft travelling 600 mph so there were less beams supporting the load.

    Here is a chart showing the strength of steel as it gets hotter, note this chart is only for 30 minutes exposure to the heat, it gets weaker the longer it is exposed to the heat. It is from MIL-HBK-5 which was the standard for aerospace metal properties, it has now been commercialized and called MMPDS, but you can find another source for this info if you like such as Marks Standard Handbook for Mechanical Engineering or probably some civil engineering reference (sorry not a civil engineer).

    Name:  Effect of temperature on the tensile ultimate strength and yield strength of low alloy steels.jpg
Views: 183
Size:  141.4 KB
    We must have pushed the post key at the same time. And I'm not a civil engineer..I'm a mechanical engineer. One who helps design naval combatants...so always with an eye towards survivability and the effect of heat/fire on the structural integrity of metal structures also known as "ships and craft".
    "Cynicism is the smoke that rises from the ashes of burned out dreams."

  4. #14
    Quote Originally Posted by PeoplesElbow View Post
    For Gods sake, the fire did not have to melt the steel, heat exposure over a period of time weakens steel but that wasn't the only factor that lead into failure.

    Heat also causes expansion of steel, the steel beams expanded inducing thermal stresses that added to the stress placed on the steel from the weight of the building. The stresses were increased due to a significant number of the supports being taken out by an aircraft travelling 600 mph so there were less beams supporting the load.

    Here is a chart showing the strength of steel as it gets hotter, note this chart is only for 30 minutes exposure to the heat, it gets weaker the longer it is exposed to the heat. It is from MIL-HBK-5 which was the standard for aerospace metal properties, it has now been commercialized and called MMPDS, but you can find another source for this info if you like such as Marks Standard Handbook for Mechanical Engineering or probably some civil engineering reference (sorry not a civil engineer).

    Name:  Effect of temperature on the tensile ultimate strength and yield strength of low alloy steels.jpg
Views: 183
Size:  141.4 KB
    So what you are saying is explosive charges planted by rouge agents conspiring within the US government brought the Towers down... got it!!!
    "Pain heals. Chicks dig scars. Glory... lasts forever." - Shane Falco

  5. #15
    Quote Originally Posted by stgislander View Post
    So what you are saying is explosive charges planted by rouge agents
    Were they wearing rouge as part of their clever disguises?

    Just curious..asking for a friend.
    "Cynicism is the smoke that rises from the ashes of burned out dreams."

  6. #16
    Power with Control glhs837's Avatar
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    Quote Originally Posted by LightRoasted View Post
    If I may ...

    Wow. Well, I was actually referring to building 7 of the trade center complex. But since you all bring it up, the towers were never fully engulfed in fire, like this building in England that was fully engulfed and burning for hours, 12 actually. There was way more smoke than fire in the towers. In addition, there was never a sufficient fuel/air mixture to produce a fire hot enough, long enough, to melt the steel support members that were designed to withstand the very thing that happened. Science is a funny thing isn't it? I'm just making an observation.
    You know the difference between melting and being weakened to point of failure under load, right? And the difference between static and dynamic loads, right? And the amount of stress in on a building the height of the 47 stories and one a little more than half that height? Science isn't funny, it just requires rigor. And either make an accusation, or don't, this "Just saying" crap is weasel words to allow you to cast poop without getting your hand dirty. you either think that some part of 9/11 was a conspiracy, or you don't. Own it or don't say it.
    "I aim to misbehave."

  7. #17
    Quote Originally Posted by Gilligan View Post
    Were they wearing rouge as part of their clever disguises?

    Just curious..asking for a friend.
    They could have.
    "Pain heals. Chicks dig scars. Glory... lasts forever." - Shane Falco

  8. #18
    Registered User PeoplesElbow's Avatar
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    Quote Originally Posted by Gilligan View Post
    We must have pushed the post key at the same time. And I'm not a civil engineer..I'm a mechanical engineer. One who helps design naval combatants...so always with an eye towards survivability and the effect of heat/fire on the structural integrity of metal structures also known as "ships and craft".
    Im an ME myself and in my structural design experience one of the things I had to design for is the strength of things affected by the heat generated by............burning jet fuel.
    If what I say offends you then you really don't want to hear what I keep to myself.

  9. 06-15-2017, 06:11 AM

  10. #19
    Quote Originally Posted by Hijinx View Post
    The twin towers was not your every day fire.
    When you have thousands of gallons of jet fuel sprayed over a two or three floors of a building and ignited it's not like some furniture and contents.
    Let's not forget the tons of Magnesium ( 3,000 + degrees ) and Aluminum Magnesium Alloys that burn alot hotter than Jet Fuel.
    Originally Posted by littlelady View Post
    I just reported you. You are one scary individual.

  11. #20
    The sad thing is, this building was probably covered with fiber-cement board (Eternit) when it was built. You can put a blowtorch to the stuff and it won't catch fire (the original version was made from asbestos ). The interior construction is mostly steel and concrete. This created an inherently fire resistant structure where an apartment fire usually remained contained to the individual unit . By covering the outside of the building in this Zinc/Aluminum/Polyethylene* composite, they created a path for the fire to quickly move from floor to floor. I am sure all the reports and assessments written at the time padded themselves on the back on how they increased the 'sustainability' of the building and kept the polarbears from drowning.







    *one of the british articles mentions polyisocyanate which would be one of the more fire-resistant versions of cladding
    Last edited by officeguy; 06-15-2017 at 07:29 AM.

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