Abstract
A variety of different materials have been considered and implemented for occupant protection in automotive head impact countermeasures since the beginning of the five-year phase of FMVSS 201 (Upper) on September 1, 1998. Polyurethane foam has been the material of choice because of its good performance, ability to maintain properties across a wide range of temperature conditions, reasonable cost, and ability to be molded into complex shapes.
In recent years, pressure to reduce costs has resulted in an increased use of lower-cost thermoplastic materials. The thermoplastic nature of some of these materials can lead to significant changes in energy management characteristics with changes in environmental conditions. This paper shows that polyurethane foams are superior at retaining their energy-absorbing characteristics over the service temperature range of 30 to 85 °C.
Keywords
Get full access to this article
View all access options for this article.