Thermoplastic Glass Mat Reinforced Knee Bolster Development

The desire to combine the roles of the instrument panel carrier with structural functions traditionally fulfilled by steel reinforcement and tie bars provided the catalyst to search for a material and construction capable of combining the advantages of plastic processing with the structural characteristics of steel. Candidate materials and constructions were initially judged against a criteria list of design flexibility, tooling cost and leadtime, piece cost, developmental leadtime, product maturity, weight,and physical properties. The most promising alternates were tooled and tested with a knee impactor and a barrier sled in order to assess performance to occupant safety objectives. Ultimately, a thermoplastic composite proved capable of meeting all the structural requirements while enhancing design flexibility and reducing tooling leadtime and cost, piece cost, and vehicle mass.