Topology optimization of an automotive hood for multiple load cases and disciplines

To reduce the head impact injuries in case of traffic accidents, the design of an automotive hood must consider many design requirements including impact of the head against the hood at different locations, be lightweight but with enough stiffness to resist various loads imposed on the hood, and have NVH characteristics such as the fundamental frequency. Methodologies to solve this type of design optimization problem that integrates multiple design criteria are rare to non-existent in the automotive design field. This paper shows how to conduct the worst-case design of the hood for multiple head impact locations, which is required by the pedestrian safety code. In addition, a topology optimization problem of the hood that combines statics, impact, and eigen frequency load cases is solved by using LS-TaSC to provide the optimal lightweight hood structure satisfying the design constraints. This is possibly the first demonstration of both the worst-case design and multi-disciplinary design optimization considering both impact and frequency load cases on an industrial problem.