Evaluation of New Methodology for Health Hazard Assessment of Repeated Shock in Military Tactical Ground Vehicles

摘要

Anecdotal reports in the mid 1980's attributed adverse health effects to whole-body vibration (WBV) exposure in U.S. Army tactical ground vehicles (TGVs), even though these vehicles passed existing WBV standards (e.g. ISO 2631-I). The U.S. Army Aeromedical Research Laboratory (USAARL) conducted a research program to develop militarily relevant methodology for health hazard assessment (HHA) of TGV rides. The research culminated with the development of a new HHA method for repeated jolt that is tailored for TGVs but is valid for most vehicles where the seated occupant is exposed to repeated (multiple) low- level shocks (jolt). In this paper, we describe the new HHA method and present results of health risk prediction by the new multiple shocks standard (ISO 2631- 5) compared to predictions by the current WBV standard (ISO 2631-I). The comparison focuses on two current indices - the weighted root-mean-square (WRMS) and the vibration dose value (VSV) that was designed to emphasize the shocks embedded in WBV as well as the equivalent daily stress dose (Sed) that was introduced in the new standard, then combines the results with the probability of utilization of a vehicle to assign a risk assessment code (RAC) as required by U.S. Army regulation Ar 40-10. Results have shown that the new standard is more sensitive to cross-country rough terrain signatures than WBV methods, but produces similar predictions for ride signatures obtained over paved or secondary roads. The data analysis demonstrates the applicability of the new ISO 2631-5 standard to tactical ground vehicles, especially in the vertical axis.