井下车用零件多裂纹扩展的时变可靠性分析

针对工程中井下车用零件的多裂纹损伤问题，通过扭转疲劳试验模拟了车用零件中传动轴的疲劳损伤，并应用长焦显微镜与照相机相结合的测量法对零件一定疲劳循环次数后的表面裂纹进行了测量统计，同时以Paris模型及剩余强度估算模型对统计数据进行处理，得到了剩余强度.再应用所建立的时变可靠性数学模型，求取了零件时变强度的漂移率及波动率，并最终得出了该零件在一定疲劳循环后的可靠度.该方法从实际应用上解决了时变理论对零部件时变强度的动态检测问题，将时变理论向工程化应用推进一步，具有良好的应用前景.

Time Dependent Reliability Analysis of Underground Vehicle’s Parts Based on Multi crack Propagation

Considering the existence of multi crack damage in underground vehicle’s parts， the torsion fatigue test for simulating the fatigue damage was built. The surface crack after certain fatigue cycles was further measured by telephoto microscope and camera， and the Paris model and residual strength estimation model were used to process the data for residual intensity. Then， the time dependent reliability mathematical model was used to calculate the drift rate and fluctuation rate of time variant intensity， and finally educed the reliability. This method solves the problem of dynamic detection of parts’ time varying intensity when using time dependent theory， and advances the time dependent theory to the engineering application. It has a good application prospect.