Crash optimization considering the head injury criterion

In the crashworthiness of the vehicle, the head injury criterion is the most significant factor in the injury rate. Crash optimization has been employed to enhance the head injury criterion value. Since the head injury criterion value is calculated from acceleration, a surrogate-model-based crash optimization method is generally used. However, when the number of design variables increases, the cost of analysis increases extremely. Conceptual design such as topology optimization is difficult to apply since it has many design variables. A crash optimization methodology that considers the head injury criterion value is proposed based on the equivalent static loads method. The proposed method calculates the head injury criterion value using the finite difference method, and the channel frequency classes filter during linear static-response structural optimization with the equivalent static loads. Two practical large-scale problems are solved to validate the proposed method. For the headform impact on the upper interior, size optimization is carried out to satisfy the constraint on the head injury criterion value while the mass is minimized. Topology optimization is performed in the case of the hood headform impact. The material distribution of the inner panel in the hood is determined to minimize the head injury criterion value.