Category Archives: videos

Hands-on exercise with end-users

During the exploitation and dissemination Workshop at the training Campus Weeze from 16.-17. April 2018 LUAS presented the BCB to end-users. The program was distributed to the visitors on give-away memory sticks. The end-users simply moved the content of the memory stick to a folder on their laptops or Mac´s (The BCB works cross-platform) and started Blender (the Fracture Modifier including BCB) directly, because no installation is needed. First we presented the simulation process step-by-step on a simple structure. Then the end-users were invited to open and simulate a prepared model of the H-shaped rehearsal building at the Weeze site . It was nice to see an Inachus partner with Blender experience to be engaged in own simulations from scratch after our presentation.

This video shows the simulation of the H-shaped rehearsal building at the Weeze site under an earthquake event. It is a processed simulation that includes the distribution of dummies. This feature is new in the BCB and was implemented after the pilot in Weeze. The distribution of large amount of human figures is made with the help of Blender´s particle system, a new preset group ‘Victims’ has been added in the BCB element groups for this purpose. Note, that the simulation of masonry structures is not yet sufficiently studied and the simulation results still may lack plausibility.


Bridge collapse in Miami- Simulation with the BCB

Video: by courtesy of Kostack Studio

Blender and the BCB were used to model and simulate the bridge that collapsed in Miami in a speed modeling challenge. Due to the lack of precise technical drawings the Bridge was reconstructed on the basis of high resolution drone images. The element properties were estimated from close up photographs of the bursted reinforcement. The bridge was built and simulated in Blender in just 24 hours.

Even though the bridge model is only estimated and the BCB has not yet formulation for pre-stressed concrete it is interesting that the damage occurred about at the same location as it happened in reality. It is to be expected  that under evenly distributed loading damage happens at the truss diagonals with the biggest internal angle,  see image below.


Training game for fast victim sorting

This is the latest student assignment that has spun off INACHUS at Laurea University of Applied Sciences this year.  Our student Juha Penttinen took on the task to proof that an effective training tool for first responders that focuses on the fast pre-sorting of victims is possible. The pre-sorting is done based on the  popular smart triage sorting algorithm that was created to tag patience with a color code to direct the ambulance at first to the victims with the most severe injuries.

The special task in this educational game is to find victims deploying various search devices like phone finder, chemical trail detector, IR- and night vision etc. All the victims in the debris need to be found and tagged correctly in the shortest possible time.

The collapsed building structure used in this game is a result of the DEM simulations (performed by the BCB software) of the Vitruv building library.

The game can be freely downloaded from here: Training game for fast victim sorting

Simulation of WT7 with the BCB

The BCB has delivered valuable results when it was used to simulate the
destruction of the Pyne Gould Corporation building in Christchurch and
the collapse of the apartment block in Chennai. Both cases have been
described in this blog earlier. Now, a third collapse simulation comes
along as another validation case, it further emboldens us to believe
that the BCB delivers noteworthy results. Kostack studio used the BCB to
simulate the collapse of the World Trade Center 7 that occurred after
the terror attack in New York in 2001. This collapse is still furiously
disputed to prove or disprove conspiracy theories that claim that the
collapse happened by controlled demolition. Kostack studio procured the
detailed construction drawings  and built an accurate model
with all relevant structural members in Blender. For the initiating
collapse event the findings of the NIST (National Institute of Standards
and Technology) investigation report were used. According to this report
the failure occurred due to the intense fires that were triggered by the
debris from the other two towers. The sprinkler system in WTC7 did not
work properly. The fire caused the thermal expansion of steel beams that
caused a girder to slide and loose its bearing which in turn caused a
vital pillar (column number 79) to buckle. In the Blender model column
79 was removed.

The load bearing structure of the WTC7 was made of steel. The steel
members were bonded with screws. To replicate these connections the
strength formulas in the BCB perform a rough approximation of the ratio
of the total screw area section and member contact area.

The Blender simulation replicates a peculiarity that is not evident when
watching the actual video footage from the collapse. The building’s
structure was a typical tube-frame design, the facade columns and beams
formed a rigid frame that delivered a strong structural membrane along
the exterior of the building. After the implied column failure the
structure collapsed from within and left the hollow membrane staying for
a while before the latter was caving in on itself as well.

This simulation is a sober re-creation of the alleged damages caused due
to the fires that were stated in the NIST report. It is not meant to
comment on any of the claims regarding the conspiracy theories.

WTC7 technical drawings:


Second pilot in France

The second INACHUS field test was held on 31 May 2017 in Lyon, France. It focused on

merging data from wide area assessment tools and collapse simulations. In collaboration with

CARDEM, a French demolition company, INACHUS partners identified a three-storey factory

building in Saint-Fons that was scheduled to be demolished. A first scenario planned to weaken

key pillars and subsequently pull the building over by ropes. It then was decided to execute a

second scenario by gradually weakening certain pillars until collapse occurred, this procedure

was designed to mimic the impact of an earthquake.

Factory before and after collapse. Pillars were progressively weakened until collapse occurred

ASI visited the building in spring to record the construction technique in order to build the

virtual building model. The model was then simulated by ASI with the second collapse scenario.

Ground-based and airborne laser scans by FOI, ONERA and ITC created a textured point cloud

model of the building before and after the collapse. The image below shows the matching of

laser scan and simulation result.

The matching of laser scan and simulation result by ASI.

The Video below shows the simulation result performed by LUAS. The DEM model (provided by

courtesy of ASI) was simulated by applying the first collapse scenario where some pillars were

weakened and where the building was  then pulled over by ropes.

The Vitruv Building Library

In order to supply rescue personnel with training material  a data base with pre-run collapse simulations was created. This building library consists of four building types that are archetypical representations of a number of commonly built structures:
1. Vitruv Building #2: a low apartment building
2. Vitruv Building #3: a high rise building with a square shaped floor plan and a center core
3. Vitruv Building #9: a high rise building with a rectangular floor plan and a center core
4. Vitruv Building #11: a historic, double wing brick building

Those four buildings have been submitted to various explosion and earthquake scenarios. Damages from detonations were defined and earthquakes with four ascending intensities from low to devastating were simulated.

This building library is expected to be extended in the future to not only serve training exercises but also allow more and more accurate predictions where hollow spaces will be formed in which victims can survive.

In the beginning the videos show a new useful BCB functionality: A mesh of the concrete rebar is generated following the definitions in the BCB´s Formula Assistant namely rebar position amount and sizes. This rebar mesh is only for diagnostics to detect obvious mistakes in the element settings and is not linked to the simulation routine.

We picked up our initial approaches (blog post from 20. Mai 2015) to visualize cavities and applied a modified version on the collapse debris mesh. We could prove that cavity can be visualized fast and directly  in Blender largely with Blender´s native inbuilt modifiers. The result can be seen in the last sequence of the videos.

Another simulation for the building library

This video shows the simulation of the second building from the building library. Two damage scenarios were examined: a pillar removal due to explosion and an earthquake. The pillar removal did not lead to collapse. The video displays the reaction when the strong earthquake time history was applied.

The building library collects a range of typical building structures (9-10 buildings) including structural details. Prone to collapse risks are examined and the collapse shapes are exported from the simulations in a digital exchange format DXF and OBJ. The building library can be used in a real collapse case to estimate the probable location of cavities.


The removal of these two pillars did not lead to collapse.