关键词: 功能梯度, 负泊松比结构, 斜向冲击, 耐撞性能

Abstract:

In the process of vehicle collision， oblique collision is more common. Through crashworthiness study of the three?dimensional （3D） negative Poisson’s ratio （NPR） lattice structure under multiple conditions， it is found that the impact angle has a great impact on the crashworthiness of the 3D NPR lattice structure. As the impact angle increases， the energy absorption value is on a downward trend. The gradient NPR lattice structure is selected as the filling material into the crash box. The wall thickness of the crash box and three gradient thicknesses of inner core are used as design variables. The maximum energy absorption， the minimum peak force， and the mass are adopted as the optimization objectives. The value range of the mass and design variables are regarded as constraints， and multi?objective optimization design is carried out under the multiple conditions based on the multi?island genetic algorithm.The results show that under the condition that the mass and the maximum peak force are basically the same， the comprehensive energy absorption of the crash box filled with NPR structure and the crashworthiness in each impact angle have been greatly improved， which means the optimization effect is obvious.

Key words: functional gradient, negative Poisson’s ratio structure, oblique impact, crashworthiness