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Why Fact-check? Why preserve a visual record?

The Website Written as a Book
Introduction
1: Science and Subjective Viewpoints
2: Toward Accurate Collapse Histories
....2.1: Progressive Floor Collapses in the WTC Towers
....2.2: General Global Characteristics of Collapses
....2.3: Mathematical Basis of ROOSD Propagation
....2.4: WTC1 Accurate Collapse History
....2.5: WTC2 Accurate Collapse History
....2.6: WTC7 Accurate Collapse History
3: WTC Collapse Misrepresentations
....3.1: Purpose of the NIST Reports
....3.2: NIST WTC1 Misrepresentations
....3.3: NIST WTC7 Misrepresentations
....3.4: NIST WTC2 Misrepresentations
....3.5: Reviewing the Purpose of NIST and FEMA Reports
....3.6: Bazant Misrepresentation of Collapse Progressions
....3.7: Block Misrepresentations of Collapse Progressions
....3.8: AE911T Misrepresentations of the Collapses
4: Scientific Institutions Can Be Unaware of Contradiction
5: Reassessing the Question of Demolition
....5.1: The Case of WTC1
....5.2: The Case of WTC2
....5.3: The Case of WTC7
6: WTC Collapse Records Studied as Meme Replication
....6.1: Meme Replication in Technical Literature
....6.2: Meme Replication in Mass Media
....6.3: Meme Replication in Popular Culture
....6.4: John Q Public and the WTC Collapse Records
Conclusions

WTC Twin Towers Collapse Dynamics

Official, Legal Attempts to Explain Collapses

Academic Attempts to Explain Collapses Reviewed

On the Limits of Science and Technology

WTC Video Record

WTC Photographic Record
WTC1 Attack to Collapse
WTC2 Attack to Collapse
WTC 7
.
-----PHOTO RECORD OF FIRE PROGRESSION-----
Fire Progression, WTC1 North Face
Fire Progression, WTC1 South Face
Fire Progression, WTC1 East Face
Fire Progression, WTC1 West Face
Fire Progression, WTC2 North Face
Fire Progression, WTC2 South Face
Fire Progression, WTC2 East Face
Fire Progression, WTC2 West Face
.
----DEBRIS LAYOUT AND CONDITION, BY REGION-----
Debris: WTC1 Around Footprint
Debris: WTC2 Around Footprint
Debris: From WTC1 Westward
Debris: From WTC1 Northward
Debris: From WTC2 Eastward
Debris: From WTC2 Southward
Debris: Plaza Area, Northeast Complex
Debris: Hilton Hotel, Southwest Complex
Debris: General, Unidentified Locations
Damage to Surrounding Buildings
Perimeter Column Photo Record
Perimeter Columns: Types of Damage
Core Box Columns: Types of Damage
Complete Photo Archive
Other Major 9-11 Photo Archives
The 911Dataset Project

WTC Structural Information

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Online Misrepresentations of the WTC Collapses

Forum, Blog Representations of the WTC Collapses

The Book Tested Through Experiments

Miscellaneous Notes, Resources
FAQ for Miscellaneous Notes
History Commons 9/11 Timeline
The 911Dataset Project
Skyscraper Safety Campaign
First and Largest 9/11 Conspiracy Theory
Key Words in Book and Website
Trapped Within a Narrowed False Choice
Vulnerability and Requestioning
On Memes and Memetics
Obedience, Conformity and Mental Structure
Denial, Avoidance (Taboo) and Mental Structure
Taboos Against Reviewing the Collapse Events
Extreme Situations and Mental Structure
Suggestibility, Hypnosis and Mental Structure
Awareness and Behavior
Magical, Religious, Scientific Cause-Effect Relations
The Extreme Limits of Mental Dysfunction
Orwell's "Crimestop", "Doublethink", "Blackwhite"
William James, Max Born: Science as Philosophy
Plato on Self Reflection and Mental Structure
Rewriting History, part 1
Rewriting History, part 2
On Smart Idiots

New Ideas in Education

Progressive Floor Collapse Simulations

Progressive Floor Collapse Simulations


PROGRESSIVE FLOOR COLLAPSE FEA SIMULATIONS




I decided to take a break from the core FEA and fiddle around with a 60 foot truss, dropping it to see the effects. These are simple models without the bridging truss. The truss is resting on the wall brackets without bolts, gusset plate, etc. The first two videos are fully elastic.



YouTube VIDEO 1



YouTube VIDEO 2


The next two videos show the collapse with plastic or yielding included. Note, there were some issues with the meshing, that is why you'll see some of the connections "stretching". Again these are preliminary simulations. The next ones should include bridging trusses.



YouTube VIDEO 3



YouTube VIDEO 4

from this post



I suppose concrete fracture is out of the question... (only talking about one slab impacting another, probably need a lot of elements)
For now, it is out of the question. Although we should never have a direct slab to slab impact. The steel from the truss will interfere.

I wonder if it is possible to run this same simulation again but amend the initiation by unclipping one side at the top rather than both. It would certainly resolve some issues.

It is something I would like to explore as well, but as will be shown, I need the simulation to drop a few more floors before any real meaningful conclusions can be drawn.


With that said, the next simulation shows what would happen when one floor drops onto the next in a purely elastic form.



YouTube VIDEO 1

YouTube VIDEO 2

I took data from the top of the upper floor.



Displacement:

Large Image

Velocity

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Acceleration of one point


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The next simulation incorporates plastic deformation or the yield in the steel.


YouTube VIDEO 3



YouTube VIDEO 4

Again, I took data from the top of the upper floor.


Displacement:

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Velocity


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Acceleration of one point


Large Image


The round area is where the model exited with an error (element distortion). It was longer than my first run with a much coarser mesh. This model took nearly 10 hours just to get to this point. I am going to need to look into using beam elements to speed up the process.


Large Image


Also note, I rested the truss on the ledge. If I were to bolt them in place and add the upper welded gusset, the times will only increase.


Large Image

from this post

Created on 09/21/2012 09:27 PM by admin
Updated on 03/23/2014 05:52 AM by admin
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