A new computer model for studying side airbag and occupant interactions was developed for the CVS/ATB multi-body dynamics program. This model employs standard CVS/ATB segment ellipsoids to represent the airbag. Bag stiffness is represented by a standard force vs. penetration contact function, however, the CVS/ATB program code was modified to allow the stiffness function to be multiplied by an additional, time dependent scaling function. This permits simple simulation of bag inflation and deflation without direct modeling of hydrodynamic bag parameters. The 5th and 50th percentile occupant models were originally obtained from the GEBOD program. These models were modified to incorporate clavicle segments. The additional shoulder freedom, permitted by extensive clavicle motion, results in significant kinematic differences between H3-type dummies and cadavers when performing side airbag tests. In the computer simulations, dummy cases are represented with a locked clavicle joint, while for cadaver cases the clavicle is permitted to move relative to the torso. This model has been exercised for a variety of potential occupant seating positions and has proven effective in distinguishing differences in load and kinematics. This in turn has helped guide the choices made for laboratory experiments such that testing efficiency is maximized. (A)
Samenvatting