Numerical Simulation Research On Airbag Working Process

Airbags are widely used in aerospace, marine, automotive and other new areas. The traditonal airbag design is mainly based on empirical formulas and physical experiments. They need enormous manpower and material resources, and the cycle is long, some important data are incomplete. But with the rapid development of hardware and software, the numerical simulation-assisted design becomes possible.Firstly, the author simulates a practical application, the entire work process of unmanned aircraft used buffer airbag, which is based on LS-DYNA with control volume method (for short as CV method). Then we obtain the pressure, velocity, overload of the airbag. Secondly, this paper also use an arbitrary Lagrangian-Eulerian (for short as ALE method) fluid-solid coupling method to simulate the inflation of airbag. We obtain the dynamic relationship between the shape and the flow field, then we analysis the flow field.At last, we compare the result with that conclude from CV method.The results show that CV method used in cushioning and other practical engineering applications calculate faster. Those applications need several times to compare in parameters such as balloon dimensions, exhaust port area and so on. The CV method is simple, but it can't get the transient flow field changes and the details of airbag surface in simulating the process of high speed inflation. This paper ensure the feasibility that ALE method can be used in simulating the airbag inflation process. Through the stress analysis of surface structure, we can obtain the dangerous location during the inflating process. In short, no matter of CV method or ALE method, they can reduce the number of trials during airbag designing, which is of great significance.