There are serious traffic accidents and large angle impact on vehicle body when a bus rolls over. In this paper, a novel local functionally graded thickness (LFGT) sidewall pillar and a minimum deformation search (MDS) method are investigated to improve the bus rollover crashworthiness. According to ECE R66 standard, there was most serious deformation of the traditional side column of the bus when the bus rolls over with large angle impact. To reduce the deformation, a LFGT tube is designed to apply to sidewall pillar. In addition, the characteristics of the LFGT tube under large angle impact are analyzed by radial basis function. From the characteristics, a MDS method is proposed to improve the rollover crashworthiness of bus body. Then, the simulation experiments are conducted to validate the influence of LFGT tube on bus rollover crashworthiness. The results show that the MDS method meets the machining accuracy and ensures the computational efficiency for bus rollover collision optimization, and LFGT sidewall pillar optimised by MDS method can improve the rollover crashworthiness of bus body.

公交车翻车时会发生严重的交通事故，并且会严重影响车身的角度。本文研究了一种新颖的局部功能梯度厚度（LFGT）侧壁立柱和最小变形搜索（MDS）方法，以提高公交车侧翻的耐撞性。根据ECE R66标准，当母线侧倾大角度冲击时，传统的母线侧柱变形最严重。为了减少变形，设计了LFGT管以应用于侧壁立柱。此外，通过径向基函数分析了大角度冲击下的LFGT管的特性。从特性出发，提出了一种MDS方法来提高车身的侧翻防撞性。然后，进行了仿真实验，以验证LFGT管对公交车侧翻防撞性的影响。结果表明，MDS方法满足了加工精度，保证了公交车侧翻碰撞优化的计算效率，采用MDS方法优化的LFGT侧壁立柱可以提高车身的侧翻防撞性。