PNGV Hybrid Material Automotive Body Structure Development 1999-01-3224

In 1997, Multimatic became involved in a project that is part of the Partnership for a New Generation of Vehicles (PNGV) program. The intent of the program is to develop technology that will allow very efficient passenger vehicles to be mass-produced. Ideally, the vehicles will offer performance and features comparable to those of current production mid-size sedans while achieving 80 mpg fuel economy. The goal of Phase 1 of the Hybrid Material Body Structure Development Project was to develop the lightest possible automotive body structure for a vehicle based on a current production mid-size sedan. The resulting design was to meet or exceed the stiffness performance of the existing steel structure while achieving the highest possible weight save. The result of this analytically based engineering study was a largely composite material body structure design that was predicted to exceed the bending and torsional stiffness of the baseline steel structure, while achieving an overall weight reduction of 70.2%.

In 1998, Phase 2 of the project was completed. Phase 2 involved comprehensive design, analysis, and fabrication stages to validate the predicted weight save and body stiffness from Phase 1. The project also involved performing a 30 mph full frontal crash simulation to demonstrate performance similar to the baseline steel vehicle. In addition, a full-scale, one-off structural demonstrator was built and a high volume manufacturing strategy, that would be applicable by the year 2004, was developed.

The result of the project was the development and fabrication of an automotive body structure that contains a creative combination of aluminum, carbon fibre, and aramid materials. The development of this structure demonstrates that a 69% body-in-white (BIW) mass reduction is possible while retaining the body stiffness, frontal crash performance, and interior package space of a comparable steel mid-size sedan.

This paper discusses the role of static finite element analyses in the development of the Hybrid Material Body Structure and the correlation of the analysis results with testing.