It looks like you're using an Ad Blocker.
Please white-list or disable AboveTopSecret.com in your ad-blocking tool.
Thank you.
Some features of ATS will be disabled while you continue to use an ad-blocker.
and besides.....this 'thermal expansion' did NOT expand steel. it is HYPOTHESIZED as a NEW PHENOMENON to REMOVE structural mass to ALLOW global unified CONSTANT acceleration to occur.....105 vertical feet of LOAD BEARING continuous vertical support....
8 floors of truss assemblies with carrier beams...
lateral, cross, and diagonal bracing throughout...
tens of thousands of bolts and welds...
Interior partitions...
office contents...
utilities....
Also, maybe you can show me where exactly in the report does it mentions anything of what you said here:
and besides.....this 'thermal expansion' did NOT expand steel. it is HYPOTHESIZED as a NEW PHENOMENON to REMOVE structural mass to ALLOW global unified CONSTANT acceleration to occur.....105 vertical feet of LOAD BEARING continuous vertical support....
8 floors of truss assemblies with carrier beams...
lateral, cross, and diagonal bracing throughout...
tens of thousands of bolts and welds...
Interior partitions...
office contents...
utilities....
NCSTAR 1A 3.6] "This free fall drop continues for approximately 8 stories, the distance traveled between t=1.75s and t=4.0s...constant, downward acceleration during this time interval. This acceleration was *9.8m/s^2*, equivalent to the acceleration of gravity."
NICSTAR 1A 4.3.4] Global Collapse..."The entire building above the buckled column region moved downward in a single unit, as observed, completing the global collapse"
Where does the NIST say a new phenomenon removed structural mass. I wanna see this exact quote, with the section numbers, page numbers, and actual quote.
Shyam Sunder at NIST technical briefing
"the phenomenon that we saw on 9/11 that brought this particular building down was really thermal expansion, which occurs at lower temperatures."
How do you think low temp expansion would remove structure the picture of the kinked rail tracks was a real BIG clue and that only required SUNLIGHT.
How hard is it for you to understand that structural members were failing most of the afternoon before it finally tipped the balance and the building came down
originally posted by: fillerfish
a reply to: cardinalfan0596
How hard is it for you to understand that structural members were failing most of the afternoon before it finally tipped the balance and the building came down
by a NEW physics phenomenon .YOU refuse to acknowledge they state....yet I provide them LIVE on video at the OWN tech briefing........
The other thing to keep in mind is that
when you have the full combustible burning, temperatures can actually go to much higher temperatures
in the steel. And, of course, the phenomenon that we saw on 9/11 that brought this particular building
down was really thermal expansion, which occurs at lower temperatures. So we had lower-you had
lower temperatures, gas that was still coming, that was heating up, so you had temperatures rising even
before the combustibles started burning a lot in a location.
I bolded the important part. FYI: 400 degree Celsius = 752F
More than 75 percent of its strength and stiffness are lost. But remember that the
probable collapse sequence was based on thermal expansion effects, which happen at temperatures
below 400 degrees. So the 10 to 20 minutes is when you have to reach all the way to 650. The time to
reach less than 400 would be substantially smaller. The ASTM E119 test does not capture critical
behavior of structural systems-the effect of thermal expansion, the sagging of floor beams and the
effect of the floor beam sagging on girders, connections and columns. In short, what we see is that the
thermal expansion of WTC 7 initiated the probable collapse sequence at temperatures below
approximately 400 degrees Celsius, and thus, to the extent that thermal expansion, rather than loss of
structural strength, precipitates an unsafe condition, the current fire resistance ratings system is not
conservative.
In general, tall buildings are very safe. We have decades upon decades of real-life experience to prove this. The collapse of World Trade Center 7 on 9/11 was a rare event. Our study has identified thermal expansion as a new phenomenon that can cause the collapse of a structure. For the first time, we have shown that fire can induce a progressive collapse. In the building community, the term "progressive collapse" means the spread of local damage from a single initiating event from structural element to structural element, eventually resulting in the collapse of an entire structure or a disproportionately large part of it. Currently, thermal expansion effects are not explicitly considered in current design practice for fire resistance ratings, and no design professional is assigned the responsibility for ensuring the adequate fire safety performance of the structural system in a fire. Architects typically use catalog test data to specify fireproofing thickness to meet the fire ratings in the building code. Structural engineers design buildings to withstand its weight and to resist earthquake and wind loads but are not required to considered fire as a load condition in structural design. Fire protection engineers design the active fire protection systems in a building, such as sprinklers, smoke alarms and -- I'm sorry, fire alarms and smoke management systems. They may or may not be called upon to assist the architect with the design of the passive fire protection systems such as fireproofing and compartmentation. World Trade Center 7, which included floor spans as large as 54 feet, had a structural system design that is in widespread use in other tall buildings. The length of floor spans is important. Longer beams can be [subjected] proportionately greater thermal expansion effects, but such effects may also be present in buildings with shorter span lengths, depending on the design of the structural system. We strongly recommend that building owners, operators and designers evaluate buildings to ensure the adequate fire performance of the structural system.
~~~~~~~~~~~~~~~~~~~~~~~~~
It did not collapse from explosives or from fuel oil fires. It collapsed because fires, similar to those experienced in other tall buildings, burned in the absence of water supply to operate the sprinklers and burned beyond the ability of firefighters to control it. It fell because thermal expansion, a phenomenon not considered in current building design practice, caused a fire-induced progressive collapse. We urge the building community to explicitly address all the effects of fire in the design of the structural system, including thermal expansion effects, in strengthening our building codes, standards and practices.
Really?? They said NEW physics phenomenon? Or are you just saying its "NEW" to make it sound more special, or sinister,
Shyam Sunder at 2008 NIST technical briefing
"the phenomenon that we saw on 9/11 that brought this particular building down was really thermal expansion, which occurs at lower temperatures."
phe·nom·e·non
fəˈnäməˌnän,-nən
noun
a fact or situation that is observed to exist or happen, especially one whose cause or explanation is in question
NCSTAR 1A 3.6] "This free fall drop continues for approximately 8 stories, the distance traveled between t=1.75s and t=4.0s...constant, downward acceleration during this time interval. This acceleration was *9.8m/s^2*, equivalent to the acceleration of gravity."
NICSTAR 1A 4.3.4] Global Collapse..."The entire building above the buckled column region moved downward in a single unit, as observed, completing the global collapse"
NCSTAR1A p.39/130
"the damage from the debris from WTC 1 had little effect on initiating the collapse of WTC 7."
NCSTAR 1A 4.2 "The probable collapse sequence that caused global collapse of WTC7 was..."
"NIST is withholding 68,246 files. These records are currently exempt from disclosure. All input and results files of the ANSYS 16 story and the LS-DYNA 47-story global collapse model that were used to simulate sequential structural failures leading to collapse."
I bolded the important part. FYI: 400 degree Celsius = 752F
...NO WHERE!
"No conclusive evidence was found to indicate that pre-collapse fires were sever enough to have a significant effect on the microstructure that would have resulted in weakening of the steel structure." NIST NCSTAR 1-3C, p. 235
In fact I would advise you to read the whole transcript yourself
The length of floor spans is important. Longer beams can be [subjected] proportionately greater thermal expansion effects,
It fell because thermal expansion, a phenomenon not considered in current building design practice, caused a fire-induced progressive collapse. We urge the building community to explicitly address all the effects of fire in the design of the structural system, including thermal expansion effects, in strengthening our building codes, standards and practices.
also a Tech Briefing for the media which goes into better detail:
you are out of your league here and are making serious rookie mistakes, especially for someone who claims to have been in the building trade for so long.
originally posted by: slipstreaming
a reply to: wmd_2008
lol.....photoshop!!!!!!!
HUGE give-away.....look at the different resolution of that EMT and the resolution of the buildings behind.....
look at the artifacts surrounding the EMT compared to the crispness of the buildings...pathetic amateurish attempt.
where is the FEMA watermark?
NCSTAR 1A 4.2 "The probable collapse sequence that caused global collapse of WTC7 was..."
which consists of the ENTIRETY of your pathetic post.....an UNPROVEN HYPOTHESIS of collapse that contains a BRAND NEW NEVER BEFORE SEEN physics phenomenon , 'HYPOTHESIZED' to take place ONLY on 9-11....NEW science they REFUSE TO PROVE through science.
now what would support this claim.....SUPPORTING EVIDENCE!!!!
NO physical evidence to support
NO like situations to compare with
just 68,000+ files of data variables that TELL the models, [their ONLY EVIDENCE], what to do, HOW to behave......to which they REFUSE TO SHOW.
also a Tech Briefing for the media which goes into better detail:
lol.....dumbed-down the media version...lol....that is why I posted the TECHNICAL briefing...
so you can push the TV version all you want to...it's made for TV.