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大客车侧翻仿真计算方法对比研究

2018-10-21司俊德孙明英

汽车实用技术 2018年17期

司俊德 孙明英

摘 要:依据GB17578-2013《客车上部结构强度要求及试验方法》中规定,以某12米全承载客车为研究对象,详细分析了直接空翻法、刚柔转换法、计算触地时刻边界条件法和计算触地时刻角速度法四种侧翻分析方法中的能量、侵入量和时间差异。结果表明,直接空翻法、刚柔转换法侵入量精度较高,但耗费时间较长;计算触地时刻边界条件法和计算触地时刻角速度法的侵入量误差在4%以内,同时可以节省大量时间,通过对误差修正后,可作为优先选用的侧翻计算方法。

关键词:侧翻仿真;刚柔转换;角速度;边界条件

中图分类号:U461 文献标识码:A 文章编号:1671-7988(2018)17-82-03

Abstract: Accordance with the GB17578-2013 Regulation(Requirements and test methods of strength for the superstructure of bus) and a 12 meters bus FE model, The paper detailly introduces four kinds of bus rollover simulation methods by LS-DYNA. By comparing the deformation results and computing time of four kinds of simulation method, The Conclusion has a important significance to improving the rollover simulation efficiency In a 12 meters bus as the research object, a detailed analysis of the direct method of rigid flexible converting method, somersault, calculating contact moment boundary condition method and calculation method of contact moment angular velocity four rollover analysis method in energy, intrusion and time difference. The results show that the direct method of rigid flexible converting, somersault, amount of invasive method has higher precision, but takes a long time; calculating the contact moment boundary condition method and calculation method of contact moment angular velocity the invasion amount within an error of 4%, at the same time, can save a lot of time, based on the error correction, can be used as the preferred method of calculating the rollover.

Keywords: rollover simulation; deformable to rigid; angular velocity; boundary

CLC NO.: U461 Document Code: A Article ID: 1671-7988(2018)17-82-03

前言

随着计算机技术的发展,汽车有限元模型的精细度快速提高。目前,大客车侧翻仿真计算模型网格数量在40万以上,仿真過程耗时较多。客车侧翻过程中可分为空翻和触地变形两个阶段,空翻过程中除轮胎发生弹性变形,其余部件可认为是一个刚体[1],且轮胎弹性变形导致整车质心位置变化可忽略,因此仿真计算中可不考虑轮胎的弹性变形。根据空翻阶段计算思路的不同,可将侧翻仿真计算方法归为四种,第一种方法是直接空翻法[2],第二种方法是刚柔转换法[3],第三种方法是计算触地时刻边界条件法[4,5],第四种方法是根据碰撞能量计算角速度法。

本文结合某12米全承载客车,首先使用HyperMesh建立整车有限元模型;其次利用动力学分析软件Ls-Dyna为求解器,阐述了四种侧翻仿真计算方法思路;……

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