损伤与断裂耦合效应的能量理论研究及应用

以Ⅰ型裂纹为主要研究对象,基于能量法和损伤能量释放率的概念,推导出一种用于描述裂纹尖端邻域内损伤场与断裂场的耦合效应参数:损伤型能量释放率.运用双G模型理论,应用ANSYS仿真分析三点弯曲梁的裂纹扩展过程,把得到的损伤型能量释放率结果与损伤断裂的参数进行对比分析.结合盖下拱坝工程有限元模型,将人工底缝前沿损伤型的能量释放率、平均损伤、能量释放率以及损伤能量释放率4者随水位变化的发展进行比较,说明该参数可以综合考虑损伤与断裂的耦合效应.此外,建立了该参数的应用模式.

Energy theory and its application to damage and fracture coupling effect

A mode Ⅰ crack was regarded as the main research focus in this study.Based on the energy method and the concept of the damage energy release rate,a parameter,namely the damage energy release rate,that describes the coupling effect of the damage field and fracture field in the crack tip neighborhood was deduced.Based on the dual-G energy criterion,ANSYS simulation was used to analyze the crack propagation process of a three-point bending beam,and the solution of the damage energy release rate was compared with the damage fracture parameters.Using the FEM model of the Gaixia Arch Dam in Chongqing,the variations of the damage energy release rate at the front of the base joint,the average damage,the energy release rate,and the damage energy release rate with the change of water level were compared,in order to demonstrate that the parameter can take into integrated consideration the coupling effect of the damage and fracture.The application mode of the parameter was also established.