WTC7 Simulation Evaluation - World Trade Center 7 Collapse Research Study @KaiKostack

Uploaded September 2017 | Updated September 2026, 11 hours ago

Simulated with completely new developed software designed for structural simulation, this revision of the old WTC 7 simulation attempt serves as validation case for the BCB software.

New in this simulation compared to the old one:
- Multiple constraints per connection are used to represent individual degrees of freedom (DOF)
- Breaking thresholds are computed from real world parameters
- Correct steel thicknesses and beam dimensions are used
- Plastic deformation is now simulated

While this simulation of World Trade Center 7 is still not 'perfect' it resembles much better the specific characteristics observed in the documentation of reality than the older model. This simulation confirms mostly the findings of NIST, it is safe to say that the columns 79 to 81 were the first columns which gave way because the removal of other columns led to much different collapses. More than that is hardly determinable, such a system behaves just to chaotic to tell what exact connection failed first. In this regard NIST might be wrong by declaring a specific failure point. However, I consider this not being an important question given the fact how compromised the structure around these three columns must have been exposed to fire for hours, a situation beyond any imaginable safety design specification.

Having said that, I want to emphasize that this video is not intended to prove or disprove 9/11 conspiracy theories. I'm deleting comments that include hate speech, so you better think twice before starting an argument about the reasons of 9/11 here. Instead, I recommend to read a neutral source like: en.wikipedia.org/wiki/9/11_conspiracy_theories to get some pros and cons instead of watching YouTube videos.

This is a private project. There are no third parties involved. There is no scientific report available. No peer review has taken place. Thanks for watching.

Old simulations from 2014: youtu.be/MSlIFXw3EGg
WTC 1 from 2011: youtu.be/4_J7ak_IZXk

Simulation Stats
----------------
Element count: 28228
Constraint count: 702962
Simulation time: 10 h + 1 h building constraints
Render time: real-time

Model Specs
-----------
Group 'Concrete' mass: 100654 t and 93 kg
Group 'Steel beams' mass: 22942 t and 844 kg
Group 'Steel trusses' mass: 765 t and 292 kg
Group 'Facade' mass: 4341 t and 782 kg
Group 'Facade roof' mass: 147 t and 608 kg
Total mass: 128851 t and 619 kg

Credits & Links
---------------
Simulation and visualization by Kostack Studio
kostackstudio.de

3D software Blender: blender.org
Simulated with Bullet Constraints Builder (BCB): github.com/KaiKostack/bullet-constraints-builder
Supported by Fracture Modifier build for better performance: blenderartists.org/forum/showthread.php?343637-Custom-Build-Blender-Fracture-Modifier

Software developed within INACHUS: http://www.inachus.eu
(Keywords: H2020, InvestEUresearch, EU-funded research, science)
at Laurea University of Applied Sciences LUAS, Finland:
inachuslaurea.wordpress.com

WTC7 Simulation Evaluation - World Trade Center 7 Collapse Research Study

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