液压模块挂车刚柔耦合动态响应特性及摆臂疲劳分析

Dynamic response characteristics and swing-arm fatigue analysis for a hydraulic modular trailer based on rigid-flexible coupling simulation

为了研究重型液压模块挂车动态响应特性及其摆臂疲劳强度的问题,基于有限元分析方法与刚柔多体动力学理论,建立挂车刚柔耦合多体动力学模型,以路面不平度作为仿真的激励信号,结合振动试验验证模型的准确性。对挂车在不同的运行工况下,进行动态响应仿真分析。将多体动力学仿真结果作为有限元分析的动载荷,计算获得疲劳分析所需要的应力时间历程,运用局部应力应变法对摆臂进行疲劳寿命预测。计算结果表明,摆臂应力集中部位出现在已发生断裂的断面位置及应力水平已进入塑性状态。挂车在B级、C级与D级路面下的运行,危险点的疲劳寿命均大于挂车使用年限。而在正弦形凹凸路面冲击下,危险点的疲劳寿命随正弦形幅值与车速增加而明显减短。根据仿真计算结果,可提出适用的运行工况以提高挂车运行安全性与运输效率。

In order to study dynamic response characteristics and swing-arm fatigue strength of a heavy hydraulic modular trailer,a rigid-flexible coupled multi-body dynamic model of the trailer was established based on the finite element analysis method and the rigid-flexible multi-body dynamics theory.The dynamic response of the model was simulated with road roughness taken as an excitation signal and verified with vibration experiment results.The dynamic response simulation analysis of the trailer was conducted with different operational conditions.The stress time histories of its swing-arm necessary for fatigue analysis were calculated with the results of the multi-body dynamic simulation taken as the dynamic load by using the finite element analysis method.The fatigue life of the swing-arm was predicted with the local stress-strain analysis method.The calculation results showed that stress concentration positions of the swing-arm appear at the cross section of fracture failure location when stress level enters a plastic state;with operational conditions of the trailer on B grade,C grade and D grade roads,the fatigue life of risk points is greater than the service life of the trailer;however,on sinusoidal uneven roads,the fatigue life of risk points decreases obviously with increase in sinusoidal amplitude and trailer speed.Reasonable operating conditions to enhance the trailer＇s operation security and transportation efficiency were proposed according to the swing-arm fatigue life simulation results.