中文摘要：

本文中利用梁单元简化模型对薄壁直梁进行概念设计阶段的耐撞性优化。首先通过赋予梁单元轴向溃缩特性，模拟薄壁梁的溃缩变形。接着对梁单元简化模型进行了碰撞仿真，将仿真结果与详细模型相对比，以分析简化模型的精度及可靠性。最后以此为基础对梁单元简化模型进行耐撞性优化。结果表明，该简化模型易于创建，且有很高的精度，可以用于薄壁梁构件概念设计阶段的耐撞性优化。

英文摘要：

In this paper, a crashworthiness optimization of straight thin-walled beam is conducted in con- cept design phase with a simplified beam element model. Firstly the axial collapse characteristics are defined for beam elements to simulate the collapse deformation of thin-walled beam. Then a crashworthiness simulation is per- formed on the simplified beam model and the results are compared with that of detailed model to analyze the accura- cy and reliability of simplified model. Finally on this base a crashworthiness optimization on the simplified beam model is carried out. The results show that the simplified model is easy to establish with high accuracy and can he used for crashworthiness optimization of thin-walled beam components in concept design phase.