Fatigue Crack Propagation Path and Life Prediction Based on XFEM

基于XFEM的疲劳裂纹扩展路径和寿命预测

¹ Aircraft Design & Research Institute, AVIC Harbin Aircraft Industry Group Co. LTD, Harbin 150000, China
² Shenyang Entry-Exit Inspection and Quarantine Bureau Technology Center, Shenyang 110011, China

Received: 4 September 2018

Abstract

Based on the theory of linear elastic fracture mechanics, the relationships between material constants c₃, c₄ required in Abaqus and constants C, m in Paris formula are derived. Then extended finite element method (XFEM) of Abaqus software is used to is used to predict the crack propagation path and life of the plate with center inclined through crack and typical stiffened wing spar with initial crack under the constant amplitude fatigue load. The results show that the predicted crack propagation path is in good agreement with the experimental results, and the crack propagation life error is less than 6.3%. It also shows that this method can accurately predict the fatigue crack growth path and life of two-dimensional and three-dimensional complex structures under constant amplitude loads. This study can provide an effective way for damage tolerance analysis of structures and has certain engineering application value.

摘要

根据线弹性断裂力学理论，推导出了Abaqus中材料参数c₃，c₄与Paris参数C，m的之间的换算关系式，并基于Abaqus软件的扩展有限元XFEM分析，分别对含中心穿透斜裂纹平板和带初始裂纹的加筋翼梁典型结构在等幅疲劳载荷下的裂纹扩展路径和裂纹扩展寿命进行了预测和试验验证。算例结果表明预测的裂纹扩展路径与试验结果吻合良好，裂纹扩展寿命误差在6.3%以内。表明该方法可以精确地预测等幅载荷下二维和三维复杂结构的疲劳裂纹扩展路径和寿命，可为结构的损伤容限分析提供有效途径，具有一定的工程应用价值。