基于扩展有限元的疲劳裂纹扩展分析

Fatigue crack propagation analysis based on extended finite element method

针对结构板裂纹扩展问题,基于Abaqus的扩展有限元法,使用3种方法计算单边裂纹和中心裂纹的静态应力强度因子,发现相互作用积分法结果更加精确,误差在2%以内。采用相互作用积分法计算裂纹扩展过程的动态应力强度因子,误差在3%以内,结合低周疲劳分析,对孔边裂纹的剩余寿命进行预测,与试验结果相比,误差为3.8%,并且疲劳裂纹扩展稳定阶段的试验结果与扩展有限元分析基本一致,证明了此方法的准确性和可行性。因此,该方法为疲劳裂纹扩展过程中动态应力强度因子计算和剩余寿命预测提供可靠的参考依据。

For the crack propagation problem of structural plate,based on the extended finite element method of Abaqus,three methods were used to calculate the static stress intensity factor of the specimens with unilateral crack and the central crack respectively.The results showed that the interaction integral method was more accurate and the error was within 2%.The interaction integral method was adopted to calculate the dynamic stress intensity factor during the crack propagation process,and the error was less than 3%.Combined with the low cycle fatigue analysis,the residual life of the specimen with hole edge crack was predicted,and the error was 5.9%by comparing with the test results.In addition,the test results in the stable stage of fatigue crack propagation are basically consistent with the finite element analysis,which proved the accuracy and feasibility of this method.Therefore,this method could provide reliable reference for calculating dynamic stress intensity factor and predicting residual life during the process of fatigue crack propagation.