基于试验场实测应变的车辆下摆臂疲劳寿命分析

Fatigue Life Analysis of Vehicles Lower Suspension Arm Based on Strain Signal Measured in Proving Ground

在海南汽车试验场强化路面环境下对某轿车下摆臂应变模拟控制点的应变进行测定,得到其应变时间历程,并进行了频谱分析。讨论了在动态环境下准静态方法的使用条件。结合有限元静力分析结果通过准静态法获得危险点的应力时间历程,利用名义应力法对下摆臂疲劳寿命进行了计算和分析。在此基础上,研究了应变模拟控制点的选取、平均应力修正算法对计算结果的影响,所得结论有助于应变模拟控制点的合理选取,并对提高疲劳寿命估算的准确度有参考价值。

The strain time history of the strain simulation control point in the lower suspension arm was measured when the car was driven on the intensified road in Hainan automobile proving ground, Then the frequency analysis was done, and the service conditions for quasi-static method were also discussed. Combining finite element static analysis result, the stress time history of the critical location was gained by quasi-static method. Fatigue life of lower suspension arm was evaluated by the nominal stress method. Based on these work, the effect exerted by the choice of the strain simulation control point and the effect of average stress revised arithmetic on the result were investigated. The conclusion is helpful to well choose the strain simulation control point, and has reference value to improve the accuracy of analyzing fatigue life. Although the research in this article is to take the lower suspension arm for an example, the research method and conclusion have also reference value to other parts.