轮式装载机半轴载荷谱编制及疲劳寿命预测

摘要

通过实测装载机半轴典型作业工况的载荷信号,编制了半轴的载荷谱,为预测半轴疲劳寿命提供了载荷条件。根据所编制的载荷谱和半轴有限元分析结果,利用Miner准则对半轴进行了疲劳寿命预测。分析了不同工况对疲劳寿命的影响。结果表明：原生土和半湿土工况造成的疲劳损伤比例达到68.6%,而其他工况造成的损伤较小。考虑到不确定因素对疲劳寿命的影响,对半轴的疲劳寿命进行了灵敏度分析。由灵敏度分析结果可知,当半轴表面有100MPa的残余压应力,可提高寿命3.7倍;载荷幅值增加10%,寿命减少80%。该方法可以为准确预测装载机半轴疲劳寿命,改进半轴结构提供参考。%The load spectra of the wheel loader axle shaft were compiled by collecting the measured shaft load signals in the typical operation conditions to provide a reliable load condition for the prediction of the shaft fatigue life.Based on the compiled load spectra and the finite element analysis of the shaft,the fatigue life of the shaft was predicted using the Miner criterion.The effects of the operation conditions on the shaft fatigue life were analyzed.The results showed that the percentage of the fatigue damage is 68.6% in the operation in the cases of primary soil and semihumid soil,and it is less in other operation conditions.Considering the effect of the uncertainties on the fatigue life,the sensitivity analysis was performed on the shaft fatigue life.According to the sensitivity analysis result,the fatigue life increases by 3.7 times when the surface residual compressive stress reaches 100 MPa,and the fatigue life reduces by 80% when the load amplitude increases by 10%.The presented approach provides a reference for predicting the axle shaft fatigue life and improving its structural design.