SIMULATION OF AIRBAG DEPLOYMENT USING A COUPLED FLUID-STRUCTURE APPROACH

This paper explores simulation techniques for airbag inflation using a coupled fluid-structure approach. The application is to be seen as an initial study on the phenomena occurring in an airbag during an Out of Position occupant impact. The application problem is an airbag that is set to impact a head form. The head form is positioned at a very short distance from the airbag. A Multi Material Arbitrary Lagrangian Eulerian technique in LS-DYNA is used for the fluid and it is coupled to the fabric structure using a penalty based fluid structure contact algorithm. The results of the head form acceleration and velocity show good agreement to the corresponding experimental results. The results also show that at the early stages of the inflation a high-pressure zone is built up between the inflow and the head form. The consequence of this is that the pressure difference between the inflow and the high pressure zone is too low for an a priori assumption of sonic flow at the inlet.