Simulation of Curtain Airbag Development with Arbitrary Eulerian Lagrangian Method in LS-DYNA

Computer simulation is a powerful tool for developing effective airbags for modern automotive industry. At the present time, most airbag calculations are based on a so-called uniform pressure technique. In the simplest case, for every time step the pressure is constant on the internal surface of the airbag and is determined from a given thermodynamic model. An extension of this method is a “multi-chamber” approach, which allows simulating a stepwise constant pressure distribution inside of the airbag. However, in this case additional empirical assumptions on the flow between the chambers should be made. Curtain airbags serve to protect occupants on one side of the vehicle and therefore they have one long dimension and possess many complex interconnected chambers. The inflating gas needs a certain time to flow from the gas generator to the distant airbag chambers. Therefore application of the constant pressure approach for simulation of the curtain airbag development is not always possible. This paper deals with development and comparison with tests of a curtain airbag numerical model which is based on the Arbitrary Eulerian – Lagrangian (ALE) method in LS-DYNA. The project is performed in the route of virtual prototype program supported by Saab Automobile AB (Sweden). ALE airbag model build is described and discussed. Test results are compared with simulation results.