Multi-objective optimization of an automotive body component with fiber-reinforced composites

In this study, the design optimization process of a vehicle front body structure made of short-fiber composites is proposed. The aim of the optimization process is to reduce the weight in consideration of quality and production characteristics. Injection molding of short-fiber-reinforced composites leads to anisotropic material properties which depend on the dimensions of the structure, a finding which is taken into account in this research. First, a basic design is derived through topology optimization that assumes linear isotropic material properties. Second, anisotropic properties are derived by an injection molding analysis for each design point and are applied to a structural analysis to consider the anisotropic properties according to the dimensions of the structure. Third, based on the analysis results, a surrogate model is created and multi-objective optimization is conducted. The Pareto region, inversely correlated with the lightweight effect, the quality and the production characteristics, is identified. The optimal solution based on the design goal is derived using the goal-programing method.