Dynamic Modeling and Rollover Simulations for Evaluation of Vehicle Glazing Materials

The objective of this study was to mathematically model several proposed vehicle glazing materials using derived force-deflection characteristics, validate the models' dynamic behavior, and use the resulting glazing models in simulations of occupant dynamics during vehicle rollover. Simulations were performed with the three-dimensional, multibody dynamics program, the Articulated Total Body (ATB) model. The contact characteristics of side windows of tempered glass; polymethyl methacrylimide, also referred to as PMMI; and polycarbonate; as well as windshields from Ford Tempos and Jeeps, were developed from headform impact tests. These characteristics were first validated by performing simulations of the headform impact tests, and were then included in rollover simulations. Previously validated simulations of belted driver and unbelted passenger dynamics during an actual rollover accident were used as the baseline simulations. The contact characteristics of each type of glazing material were substituted for the window and windshield functions used in the accident simulations, and new simulations were run. Additional parametric simulations were run using modified contact characteristic parameters in order to determine which features of the force-deflection curves are the most important for reducing injury risk. For all the rollover simulations, the resulting head accelerations, 36 msec Head Injury Criteria (HIC) values, neck forces and torques, glazing energy absorption, and containment are obtained.