Structural Optimization with Alternate Materials–Minimum Mass Design of the Primary Structure

This study investigates the mass reduction potential of various materials which could be used in the primary structure of a front-wheel drive compact car. An in-house structural optimization computer program produced alternate designs with mild steel, HSLA steel and aluminum, as well as continuous fiber graphite-epoxy and glass-epoxy composites. For each alternate material, the design was optimized to find a minimum mass structure which would satisfy the comprehensive set of design criteria. Compared to the baseline design at 106 kg, structures made entirely with HSLA steel, aluminum, or graphite-epoxy reduced the mass by 15 percent, 26 percent, and 60 percent, respectively.

An algorithm for selective replacement of strength constrained members with alternate high strength materials was developed and evaluated.