悬架下摆臂的疲劳寿命分析

摘要

根据汽车悬架下摆臂所受的极限静载工况下的结构应力分析、道路载荷作用下的疲劳损伤分析和常用行驶工况下的疲劳寿命等分析,采用CAE与台架和道路试验相结合的方法,从多体动力学得到载荷值,应用“惯性释放法”获得不同工况下,下摆臂的应力分布特征；据此确定易出现疲劳损伤的部位,为下摆臂探索出一种一体化疲劳寿命分析方法；采用该方法对某型汽车下摆臂进行分析的结果表明,受到的应力下降1OMPa时,疲劳寿命约能提高1倍.%Based on the analyses on the structural stress of static loads in extreme condition, the fatigue damage under road loads and the fatigue life in normal driving conditions for lower suspension arm and combining CAE technique with road test, the load values are obtained with multi-body dynamics, and by applying inertia relief method the stress distribution features of lower suspension arm are acquired, and based on which the locations are i-dentified where fatigue damages are easy to occur. Thus an integrated fatigue life analysis technique for lower suspension arm is explored, using which the analysis on the lower suspension arm of a real vehicle is conducted with a result showing that for this specific situation a reduction of stress by 10 MPa can lead to nearly a doubling in fatigue life.