This paper describes the development of an enhanced airbag model for the Articulated Total Body (ATB) Crash Victim Simulation program. It consists of a number of new features and some features of the existing bag model have been modified. The new model can be implemented on minicomputers, workstations and 80386/80486 based microcomputers. The features of the enhanced airbag model discussed are: (1) a revised thermodynamic model which allows for gas flow to be input as a mass rate table and an optional temperature table for the temperature of the inflator; (2) an enhanced bag deployment model that allows for several input options to describe the bag shape during deployment; (3) general bag shape algorithm that allows modelling of an elliptical cylinder with ellipsoidal caps; (4) a revised model to describe impact between the airbag and the occupant during the unfolding of the bag; (5) allowance for the input of bag shape during deployment as a time-history table; (6) a simple folding model to calculate the effects of the bag impact during deployment; and (7) a revised contact force calculation between the bag and external segments and planes. This includes an explicit calculation of the contribution of bag tension. The paper also presents the results of the theoretical and initial validation of the model.
Abstract