SSI临界面法预测扭动微动局部疲劳裂纹萌生特性

Prediction of Local Fatigue Crack Initiation Characteristics of Torsional Fretting by SSI Critical Surface Method

以Gcr15钢球、PMMA平面试样为研究对象,建立扭动微动ANSYS有限元模型,分析得到不同工况及载荷步下球与平板接触面的接触状态及应力、应变值.转换扭动微动模型,将切向微动的SSI临界面法应用于扭动微动,研究不同法向载荷、扭转角度幅值、摩擦系数下接触面最大SSI值及其位置.结果表明:SSI最大值位于接触区的粘滑交界区间及各因素对SSI值分布影响与理论、试验试样裂纹萌生规律一致;SSI临界面法可应用于扭动微动.

The ANSYS finite element model of the Gcr15 steel ball and PMMA plane was established,and obtain the contact state,the stress and strain values of the contact surface between the ball and the plate under different conditions and load step.The SSI critical surface method of tangential fretting was applied to torsional fretting,and the maximum SSI value and position of the contact surface under different loading,torsion angles and friction coefficient was studied.The results show that the maximum value of SSI is in the stick slip boundary of the contact zone,and the influence of the different factors on the distribution of SSI value is consistent with the theory and experiment.The SSI critical surface method can be applied to torsional fretting.