The deployment of an airbag is a very complex physical process. In cooperation with the company ESI, we develop a software tool for the producers of automobiles and airbags, which is able to simulate the deployment process of an airbag very well, even if the airbag is folded in a very complex manner. The simulations carried out with this tool are supposed to provide better information about the interaction of the deploying airbag and the passengers of the car. The underlying problem is the question of injuries, i.e. the question whether the airbag actually reduces injuries in the case of an accident, or even causes more damages in certain situations.
Simulation with FPM
In the simulation, the dynamics of the gas in the interior of the airbag is dealt with at each time step by the finite pointset method (FPM) developed at the Fraunhofer ITWM. Essentially, the application of FPM yields the pressure distribution at the airbag membrane.
A second finite element software, developed by the company ESI, then describes the dynamics of the airbag membrane depending on the pressure distribution, resulting in the new airbag geometry. This new geometry is used as input for FPM in order to compute the gas dynamics of the next time step. Thus, the full dynamics of the membrane during the deployment process is determined successively. The acceleration of the membrane is the main reason of the forces to which the passenger is subject.
We were already able to prove that FPM yields very exact results, which was shown by experiments with unfolded airbags.
Type of Project: Industry Project
Project Partner: PSI/ESI, Paris-Rungis