Structural Optimization for Vehicle Pitch and Drop

The optimization method and CAE analysis have been widely used in structure design for crash safety. Combining the CAE analysis and optimization approach, vehicle structure design for crash can be implemented more efficiently. One of the recent safety desirables in structure design is to reduce vehicle pitch and drop. At frontal impact tests with unbelted occupants, the interaction between occupant's head and interior header/sun visor, which is caused by excessive vehicle pitch and drop, is not desired in vehicle crash development. In order to comply with the federal frontal crash requirements for unbelted occupant, it is necessary to manage the vehicle pitch and drop by improving structure design. In this paper, a systematic process of CAE analysis with optimization approach is applied for discovering the major structural components affecting vehicle pitch and drop. The process is composed of conducting CAE simulations with a DOE matrix, generating surrogate models, and performing the sensitivity study and design optimization. Based on the results of design optimization, some design concepts are proposed. The improvements of vehicle pitch and drop are also verified by CAE simulations.