Abstract:

This study describes a health hazard assessment (HHA) method for evaluating human exposures to repeated shocks in tactical ground vehicles. The method predicts the risk of injury to the occupants of a vehicle from the accelerations measured at the seat. The HHA will identify both acute and chronic health risks resulting from either a single exposure, or from multiple exposures to travel over rough terrain. The HHA is based on existing models, human injury data, and experimental data obtained from volunteers subjected to a range of shock profiles and to prolonged repeated shock exposures. The HHA consists of three components: (1) dynamic response models which predict seat-to-spine transmission of acceleration; (2) a dose model for exposure to repeated shocks based on fatigue failure theory and subjective tolerance data; and (3) an injury risk model based on the cumulative probability of failure. A biomechanical model is also described which analyzes spinal compression forces in response to shock. This model uses human experimental data to provide an independent evaluation of the HHA. The components of the HHA are outlined and some test results are presented. [Work supported by US Army Med. Res. & Dev. Command, Contract No. DAMD17-91-C-1115.]