Search Results

This paper describes ongoing research conducted by the National Highway Traffic Safety Administration (NHTSA) to evaluate the potential of safety restraints on large school buses. School bus transportation is one of the safest forms of transportation in the United States. Large school buses provide protection because of their visibility, size, and weight, as compared to other types of motor vehicles. Additionally, they are required to meet minimum Federal Motor Vehicle Safety Standards (FMVSS) mandating compartmentalized seating, emergency exits, roof crush and fuel system integrity, and minimum bus body joint strength.

IN A ONE YEAR LABORATORY STUDY, a side impact sled was designed, built, and validated. Using the sled and a newer generation of side impact dummy, a number of energy-absorbing materials were tested and superior materials identified. Initially this study concentrated on the crash test data for a number of V.W. Rabbits crashed in a previously completed study. The crashed vehicles were obtained, and interior crush tests were performed with a specially designed body form. This was done to determine how the effective stiffness (as seen by the occupant of the struck vehicle) of the interior door increases as the bullet vehicle presses against the interior door trim from the opposite side. An acceleration-type sled buck was then designed and built with an “interior door” mounted to mimic the interior stiffness determined from the crush tests. The sled was dynamically tested with a Haversine sled pulse similar to the door crash pulse.

The objectives of this paper are to establish a reasonable procedure for padding selection (for head/A-pillar protection) and to demonstrate how the procedure would be applied in a particular vehicle. The objectives are met by a four step procedure: 1. Theoretical analysis of material properties and the effect of padding materials on head responses, 2. Static or quasi-static and dynamic evaluations of the material properties, 3. Preliminary evaluation of the protective capabilities of the materials by simulated A-pillar component testing, and 4. Final evalution of the most promising material candidate by component testing the material installed on the upper A-pillar of a 1981 Chevrolet Citation.