Finite point method: a new approach to model the inflation of side curtain airbags

Abstract

Since its invention in the early 1990's, the side curtain airbag has become an important part of the occupant restrain system. In order to optimize the design of these devices more efficiently, Computer Aided Engineering (CAE) is often used. While usual simulation tools have proven their usefulness with certain types of airbags, the specificity of a side curtain airbag highlighted some of their limitations. The widely adopted uniform pressure method can simulate the behavior of a side curtain airbag after its full deployment, but is unable to capture the correct inflation kinematics at the early stage due to the great difference of pressure and temperature from one end of the airbag to the other end. As the result of coupling a Computational Fluid Dynamics (CFD) code with a Finite Element (FE) code, the Finite Point Method (FPM) is able to simulate the gas dynamics inside the airbag, thus results in more realistic inflation kinematics. In this paper, the simulation of a side curtain airbag by FPM and the results validation are discussed in detail. The good correlation of both flat airbag and folded airbag simulations with test data proved FPM's capability to help the side curtain airbag design by reducing the number of physical tests. Such a time and cost effective tool also provides a better chance for airbag design optimization.