Airbag Inflator Models in LS-DYNA ®

New inflator models for the automotive air bag are developed for the pyrotechnic and hybrid inflation modes. Several propellant examples including Sodium azide(NaN 3 ), Azodicarbonamide(C 2 H 4 N 4 O 2 ), and Guanidine nitrate(CH 6 N 4 O 3 ) are designed for users. To control the gas compositions into the airbag and the flame temperature in the combustion chamber, we modified an existing chemical equilibrium code, PEP(Cruise,1973) and provide a user-friendly code for users to develop their own propellant models. The inflating process is modeled by applying basic conservation laws to the several sub-sections of the inflator. Unlike existing inflator models, a new theoretical approach in a LS-DYNA model is provided. Advantages and disadvantages are discussed for the pyrotechnic and the hybrid models. In addition, we make available detailed descriptions of keyword files with comprehensive examples for the propellant ingredient control, cold and heat flow setup, and output file format options, which can be used to continue the air bag simulation with LS-DYNA’s ALE, SPH, and CESE airbag simulation capabilities.