Airbag Simulation And Application Based On CPM

As supplemental restraint system, airbag is designed to ease the secondarycollision impact between occupant and vehicle in a car accident, compensatingeffectively for the limitations of seatbelt to protect the crew’s head or something else.This paper carries out a study of folded airbag simulation and application based onCPM (Corpuscular Method) theory. Firstly, pressure vessel filling process andout-of-position pendulum test with a folded airbag were simulated in LS-DYNA,aimed at analyzing the interaction between folded airbag and out-of-position occupantchest after proving the performance of mass flow and temperature for gas generator toverify the reliability of the CPM on simulating airbag deployment process. Secondly,the static deployment of folded airbag was simulated with the CPM and UP (UniformPressure) methods. Comparison of simulation results indicates that the CPM is capableof simulating high speed gas flow inside airbag. The larger number of particle set inCPM, the smoother the Maxwell-Boltzmann velocity distribution and closer to relevanttheory curve. It demonstrates that the CPM simplifies the behavior of gas molecules inorder to equivalently emulate the high speed gas flow of initial stage of airbagdeployment. The CPM is an efficient numerical analysis method to simulate thedeployment process of airbag, and can substitute the UP method for studying theinteraction between out-of-position occupant and airbag. Last but not the least, with theinstallation of folded airbag on occupant restraint system, vehicle frontal crash test wasmodeled in LS-DYNA. Based on the CPM, the folded airbag deployment wassimulated to compare experimental and numerical results about the dummy head injury.It was found that the CPM simulation is in close proximity to the test results. Moreover,working process of occupant restraint system and protection of airbag and seatbeltwere analyzed in details combined with the basic model after validation.