Design optimization of a carbon fiber reinforced composite automotive lower arm

Abstract

Substituting composites for the metallic structures has many advantages because of the higher specific stiffness and higher specific strength of the composite materials. In this paper, we designed an automotive composite lower arm using carbon-epoxy composite materials. To optimize the stacking sequence of the composite layer, we used a micro-genetic algorithm and investigated its effects on the performances of a lower arm, such as static/buckling load capability and stiffness. To maximize the buckling load capability, we performed the design optimization with the linear perturbation eigenvalue analysis, targeting a 50% weight reduction of conventional steel lower arm. We verified again the performance of the optimized composite lower arm using the static Riks analysis technique. Finally, we found that our composite lower arm had two times higher stiffness and buckling strength compared to the conventional steel lower arm while having 50% less weight.