高强钢疲劳裂纹扩展速率的仿真模拟分析

Simulation Analysis of Fatigue Crack Growth Rate for High Strength Steel

采用相互作用积分法通过ANSYS软件对疲劳裂纹扩展过程进行模拟,并求解应力强度因子。根据试验数据利用MATLAB确定指数模型相关参数,拟合得到指数模型疲劳裂纹扩展速率曲线。将ANSYS所得的应力强度因子与指数模型相结合得到的裂纹扩展速率曲线和指数模型拟合的速率曲线二者与Paris模型速率曲线对比。结果表明:仿真所得的应力强度因子与指数模型相结合所得疲劳裂纹扩展速率曲线比指数模型所拟合出的速率曲线更加贴近Paris模型,这对于分析同类材料的疲劳裂纹扩展速率提供了参考,对分析机械结构的疲劳可靠性具有重要意义。

The fatigue crack growth process is simulated by using the method of the interaction integral through ANSYS software and the stress intensity factor is solved. According to the test data( a-N relation),using MATLAB to determine the correlation parameters of exponential model,the fatigue crack growth rate curve of exponential model is fitted. By combining the stress intensity factor of ANSYS with the exponential model,the rate curve of the crack growth rate curve and the exponential model fitting is compared with the rate curve of Paris model. The results show that the fatigue crack growth rate curve of the simulated stress intensity factor combined with the exponential model is more close to the Paris model than that of the exponential model,which provides a reference for analyzing the fatigue crack growth rate of similar materials,and is of great significance for analyzing the fatigue reliability of mechanical mechanism.