基于改进型梯度法的客车侧翻一步碰撞算法精度改进研究

Improvement Research on the One-Step Algorithm for Bus Rollover Collision Based on the Improved Gradient Method

基于改进型梯度法,对客车侧翻一步碰撞算法初始解各节点的广义失衡力进行平衡迭代,并将局部摄动思想引入改进算法的节点广义失衡力平衡迭代过程,快速获得侧翻碰撞结构的最终变形,与原始牛顿-拉夫森(Newton-Raphson)方法相比,在保证模拟精度的同时,提高了计算效率。应用改进算法对某款长12 m的公路客车典型车身段模型进行侧翻碰撞模拟,并将仿真结果与原始算法仿真结果及侧翻试验结果进行对比,结果表明,改进后算法精度基本保持不变,计算时间缩短2/3。

The generalized imbalanced forces of each node of the initial solution of the one-step algorithm for bus rollover collision are iterated to balance based on the improved gradient method.Meanwhile,the local perturbation method is introduced into the equilibrium iteration process of the generalized imbalanced forces of the nodes of the improved algorithm,and the final deformation of rollover collision is quickly obtained.Compared with the original Newton-Raphson iteration method,computational efficiency of the new algorithm is improved,and the simulation precision of the one-step collision algorithm is also guaranteed.A case study on rollover collision for a typical 12 m bus body section is carried out using the improved one-step collision algorithm,and the simulation results are compared with that of original algorithm and rollover test results,which indicate that precision of the improved algorithm basically remains unchanged,and the computation time is shortened by two thirds.