Two New Areas Concerning Side impact Protection for Passenger Car Occupants

In vehicle crash accidents, approximately 27% to 30% of passenger car occupant casualties are attributed to side impact accidents. The annual death toll in side impacts for passenger car occupants reached 9,000 in 1975 and 1976 and has been between 7,000 and 8,000 in the 1980's. Since 1977, the National Highway Traffic Safety Administration (NHTSA) and many other groups have conducted a significant amount of research on occupant side impact protection with emphasis on thorax injury reduction.

Three important problem areas in the side impact are (1) thorax-to-side interior impact, (2) head impacts with A-pillar/roof rail components and (3) occupant ejection through side doors/windows. While the first problem area has been thoroughly studied, the remaining two areas are seldom discussed and less well understood. Therefore, they are relatively new areas to many people. Since a large number of occupants are involved in these two areas, the potential for injury reduction could be very significant. The purpose of this study is to identify the nature and the extent of these problems and to explore injury mitigation concepts which may be easily applied to enhance side impact protection. A detailed accident data analysis and several experimental and analytical studies on potential safety approaches were carried out. The results show that the head impact problems are very well defined and effective safety countermeasures are readily available. Also, ejection mitigation is a valid approach for occupant injury reduction. Due to the complex nature of ejection problems, more work is required to determine performance requirements for ejection mitigation.