材料线弹性断裂力学的断裂准则研究进展

Research progress of fracture criteria in linear elastic fracture mechanics of materials

断裂准则在预测含裂纹材料发生破坏的时间、位置和裂纹扩展路径等方面具有重要意义。重点总结了线弹性材料中裂纹的断裂准则,阐述了应力强度因子准则、最大能量释放率准则、最大拉应力准则、最大拉应变准则、最小应变能密度准则等常用的断裂准则理论及其现状,以及这些准则的优点和局限性;基于常用断裂准则对应力分量和临界半径考虑不足,归纳了国内外学者提出的修正断裂准则,包括考虑T应力(非奇异项)和可变临界半径rc的影响。分析了断裂准则在岩石和混凝土脆性材料中的应用,针对基于断裂准则预测其破坏行为时存在的难题,建议将裂纹尖端应力场的高阶项T应力引入断裂准则,能更准确地预测裂纹的扩展路径与偏转角。

The fracture criterion is of great significance in predicting the time,the position and the crack propagation path for materials containing crack.In this paper,the fracture criteria of the linear elastic materials are reviewed,including the common fracture criteria,such as the stress intensity factor criterion,the maximum energy release rate criterion,the maximum tensile stress criterion,the maximum tensile strain criterion and the minimum strain energy density criterion,as well as their advantages and limitations.In view of the insufficient consideration of the stress components and the critical radius in the commonly used fracture criteria,some modified fracture criteria were proposed at home and abroad,including those considering the influence of the T-stress(non-singular term)and the variable critical radius rc.The application of these fracture criteria in brittle materials such as rock and concrete is analyzed.In view of the problems existing in the prediction of the fracture behavior based on these fracture criteria,it is suggested that the propagation path and the deflection angle of the crack can be predicted more accurately when the T-stress,the higher-order term of the stress field at the crack tip,is considered.