一种随机裂纹结构的裂纹扩展路径分析方法

裂纹结构中存在大量不确定性因素，如裂纹长度、材料性质、外部载荷等，裂纹扩展路径的不确定性分析对研究随机裂纹结构损伤和断裂的力学特性并预测其性能及可靠性具有重要意义。本文提出了一种适应于混合载荷模式下随机裂纹结构的裂纹扩展路径分析方法。该方法考虑了裂纹长度、材料性质和外部载荷等的随机性，并通过蒙特卡洛方法对随机参数空间进行采样。采用比例边界有限元方法计算结构应力强度因子，进而模拟单次裂纹扩展路径。在此基础上，通过概率分析方法获得随机裂纹结构中裂纹扩展路径的统计特性。最后给出了两个数值算例验证了本文方法的有效性。

A CRACK PROPAGATION PATH ANALYSIS METHOD OF RANDOM CRACKED STRUCTURE

There are many uncertainty factors such as crack length, material properties and external load, etc in cracked structure, and the crack propagation path uncertainty analysis is necessary for a better understanding of their mechanical properties including damage and fracture and predicting the performance and reliability. This paper proposes a crack propagation path analysis method in random cracked structure, which is suitable for mixed-model load. The method takes into consideration the randomness of crack length, material properties and external load, etc and adopts the Monte Carlo method to random sampling from random parameter space. The scaled boundary finite element method is adopted to calculate the stress intensity factors and simulate the crack propagation path. On this basis, a statistical analysis method is presented to obtain the crack propagation path statistical properties in random cracked structure. Finally two numerical examples are presented for verification of the validity of the proposed method.