Playing with LS-DYNA

In 2016 the computer magazine c't in cooperation with the ADAC crashed a LEGO® model of the Porsche GT3 RS. Consequently, some DYNAmore colleagues have asked themselves whether it is possible to do this virtually with LS-DYNA. Simply mesh all LEGO® bricks, assemble the model on the fly and check the ADAC result in the computer. A variety of urgent tasks and the sheer size of such a project made the idea fade into the background in the following months.

Up until Christmas Marko Thiele built a small crash test facility for his children for the Scale-LEGO® car. This revived the viral idea and over the Christmas holidays DYNAmore colleagues from Columbus (Ohio, USA), Versailles (FRA), as well as Stuttgart and Ingolstadt (Germany) have been competing with each other by meshing hundreds of LEGO® bricks based on publicly available CAD data. Who would get the most bricks meshed in the shortest time? This globally distributed cooperation was coordinated by the simulation data management system LoCo of Scale GmbH. Accompanied by code additions from SCALE colleagues, the overall model could thus be assembled automatically from LEGO® individual building blocks successively and, above all, promptly.

Material models were calibrated in the DYNAmore laboratory, as were the contact settings for the actual clamping forces. Thanks to the parallel development, the model was ready after a short time and delivered robust forecasts. Only the model size was slightly out of line: Due to the many geometric features of the LEGO® bricks, very fine discretization was required, which ultimately led to a model size of almost 20 million elements.

With the trump card of an executable and within limits actually predictable finite element model of the LEGO® Porsche, we contacted the editors of c't - with the result that we were given the challenge of predicting the result in a EURO-NCAP side impact. The second crash object should be the new model of the Bugatti Chiron. Of course, only a few dozen new LEGO® bricks had to be meshed - the rest of the construction task was almost automatically done by LoCo. The total model size of the car-to-car crash is now around 46 million elements and made the next step necessary: In order to obtain results promptly, we had to switch to the machines of the High Performance Computing Centre Stuttgart (HLRS). This was also where part of the post-processing took place later. Our best thanks to Martin Bernreuther for the professional support!

You can find the whole crazy story and the result in the current c't (issue 21). In issue 22 there is a real comparison to the LEGO® side impact test carried out by the ADAC-Technikzentrum in Landsberg am Lech.

More information at c't and Heise.

And at our Youtube-Channel.

Figure shows rendered simulation.

LEGO® is a trademark of the LEGO Group of companies which does not sponsor, authorize or endorse this investigations.