基于刚弹耦合多体动力学仿真的沙滩车下横臂疲劳寿命预测

Fatigue life prediction for lower arm of ATV based on dynamics simulation of the multi-body coupled with rigid and elastic bodies

针对某沙滩车,结合机械系统疲劳分析和模态分析的基本理论,以NASTRAN软件为分析工具,对悬架的关键受力部件下横臂进行模态分析。将下横臂的模态中性文件(MNF)重新导入AD-AMS/CAR软件中取代刚体下横臂模型,最终建立了刚弹耦合的沙滩车整车模型。利用MATLAB软件编制的路面谱模拟B级路面模型,将上述刚弹耦合整车模型在ADAMS/CAR RIDE环境中进行平顺性仿真,提取出下横臂与车身连接处的载荷时间历程曲线。最后,根据应力疲劳分析法(S-N分析法)和上述载荷历程曲线,在FATIGUE软件中对下横壁进行了疲劳寿命分析,分析结果为下横臂的结构设计提供参考。

According to the theory of fatigue and modal analysis for mechanical system,modal analysis for the essential part of suspension of an ATV is done in this paper based on software NASTRAN.Then a rigid-flexible ATV model is constructed by importing MNF of the lower arm once more into software ADAMS/CAR to replace the lower arm model of rigid body.At the same time the rigid-flexible ATV model is simulated for its ride in ADAMS/CAR RIDE environment with the road spectrum compiled by MATLAB to simulate B level road model and,extract the load time curve of the joint between the lower arm and body.Finally,fatigue life analysis for the lower arm is carried out in FFATIGUE according to stress fatigue analysis（S-N analysis）and the load time curve above,which results provide reference for the structural design of the lower arm..