Simulation of a shake table test

LUAS replicated a shake table test experiment that was conducted at the University of Auckland to study the resilience of typical local masonry structures and the improvements by retrofitting measures. Blender and the BCB was used to remodel the shake table structure and expose it to the same seismic pattern that was used in the laboratory. This test showed interesting affinities but also deviations that are hoped to be addressed in a future joint cooperation. Discussions are going on how Auckland can contribute their distinct knowledge in masonry dynamics and to implement simplified strength formulation. This would extend the functionality of the BCB to enable the simulation of masonry building in addition to concrete structures. Eventually Blender and the BCB could be used to efficiently simulate the effects that a major earthquake has on large historical neighborhoods.


The collapse of the Morandi bridge

On August 14 the Morandi bridge in Genoa collapsed partially. A 200
meter long roadway section fell 15 meter on the below apartment houses.
In the course one of the massive pylons collapsed as well. The tragedy
claimed the lives of 43 people. This bridge was part of the A10 motorway
that is the main link between the Italian and French riviera. This
accident is one of the big tragedies that come unexpectedly and live
long in our memories. It it makes us ponder over the safety of similar
old structures that eventually would need urgent repair.

The reason of the collapse of the Morandi bridge is currently hotly
debated. Much hints to a lack of maintainance and a resulting failure of
structural member. But also the heavy weather conditions with a
Thunderstorm and a lighting impact are often blamed.

Most theories point to the failure of one of the suspension cables. The
BCB was used to systematically analyze the presumed collapse episode and
debris shape for the failing of each of the four suspensions. The
simulations were performed by Kostack Studio.

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.

The third field test in Weeze

The 9th plenary meeting  was successfully held in the Weeze training base  at  the German-Dutch border on April 16-17, 2018. The plenary meeting was followed by the exploitation and dissemination Workshop on Wednesday 18th and Thursday 19th. The partners had a chance to present their work to end users. Fifteen urban search and rescue (USaR) professionals from Sweden, the Netherlands, United Kingdom and UN-OCHA attended.

BCB-Tutorials for beginners and advanced learners

We have finally published a series of three tutorials that introduce the BCB. This series offers something for everyone: users without any Blender experience, people who want to take on the challenge to dive into the BCB methodology and for those who just want to see results fast.

1. Guide for BCB Installation & Simple Collapse Simulation
– installation instruction and introduction into a simple collapse simulation
2. Guide to Simulate a Multi-Family House with Standard Blender
– Introduction of the BCB fundamentals with standard Blender
3. Guide to Simulate a Multi-Family House with Fracture Modifier
– Introduction into a speed optimized variant with the FM

Have fun! And please post us your own simulation results.

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.


Bridge collapse in Miami

On 15th of March 2018, a 53 m long recently-erected bridge section collapsed under its own weight. At the moment of the accident construction workers were working on the north end of the bridge section, re-tightening internal cables to strengthen the diagonal members- cracks in the structure were noticed short time before.
The bridge applied a new method, called “Accelerated Bridge Construction”, prefabricated bridge elements are hereby prepared in a factory, then shipped to the site and put together at the scene to minimize the impact on the local traffic. The exact reasons of the collapse are still being investigated.