ANALYSIS OF STRUCTURAL DEFORMATION IN VEHICULAR DROP STUDIES

摘要

Various tests are used to evaluate the roof strength of production vehicles. Dynamic rollover tests have been conducted as part of FMVSS 208 and static evaluation using FMVSS 216. The National Highway Transportation Safety Administration (NHTSA) is investigating methods to upgrade FMVSS 216 roof crush resistance to reduce injuries and fatalities in passenger cars, pickup trucks, vans, and multipurpose passenger vehicles from roof intrusion in rollover crashes (1). Roof crush intrusion is estimated to occur and potentially contribute to about 26 percent of serious or fatal injuries. Motor vehicle rollovers have been a concern for more that 30 years because they carry a very high risk of occupant death or risk compared to other types of crashes (2). The Insurance Institute for Highway Safety (IIHS) indicates that average single vehicle crashes involving rollovers accounted for about four times more deaths for registered vehicles in 1999 compared with multiple vehicle crashes (3). Twenty-six percent of all light vehicle fatalities occurred in single vehicle rollovers. A dynamic drop test onto the roof has been used by NHTSA to compare production vehicle roofs with the static 216-type evaluation (4). Roof strength improvements have been possible with the addition of polyurethane, or structural modification (5,6,7). Automotive manufacturer indicates a vertical drop test up to 1m is done on their vehicles (8). Improvements in roof structure of production vehicles have been evaluated with vertical drop tests (9). The intrusion velocity of the production vehicle roof versus the strengthened roof has been evaluated (10,11). New methods for the study of roof crush have been advanced (12,13). This study was conducted to evaluate the structural dynamics of the production and modified vehicles during an inverted vertical drop experiment.