基于裂纹扩展作用下的岩石损伤力学模型  

Microcrack Propagation-Based Damage Mechanics Model of Rock

作　　者：彭志雄 曾亚武[1] PENG Zhi-xiong;ZENG Ya-wu(School of Civil Engineering,Wuhan University,Wuhan 430072,China)

机构地区：[1]武汉大学土木建筑工程学院,湖北武汉430072

出　　处：《东北大学学报（自然科学版）》2022年第12期1784-1791,共8页Journal of Northeastern University(Natural Science)

基　　金：国家自然科学基金资助项目(41772308)。

摘　　要：在分析裂纹起裂与扩展规律基础上,考虑翼裂纹间的相互作用,提出了一种新的翼裂纹尖端I型应力强度因子计算模型.基于修正的翼裂纹扩展模型,考虑损伤演化对被激活微裂纹数目的影响,并结合宏-细观损伤定义之间的关系,建立了基于微裂纹扩展作用下的岩石损伤本构模型.最后,将理论模型曲线与试验曲线进行了比较分析.结果表明:修正的翼裂纹扩展模型不仅能够准确地预测翼裂纹的起裂角,而且能够准确地模拟从极短到很长的翼裂纹整个变化范围.基于裂纹扩展作用下的损伤模型能够连续地模拟不同围压下的应力-应变全过程曲线,而且能够较好地预测峰值强度.Through studying the cracking and propagation law of compressive-shear cracks in rock under remote stress field, a new calculation model for the mode-I stress intensity factor at wing crack tip was proposed by considering the interaction of wing cracks. Based on the modified wing crack propagation model, considering the damage evolution on the number of the activated microcracks, a microcrack propagation-based damage model for rock was established by combining the relationship between macro-micro definition of rock damage. Finally, the theoretical curves of proposed damage model were compared with the experimental curves. The results showed that the modified wing crack propagation model can not only accurately predict the cracking angle of wing crack, but also simulate the whole range of variation of wing crack length from being extremely short to very long. The microcrack propagation-based damage model can not only continuously describe the stress-strain curves under different confining pressures, but also predict the peak strength well.

关 键 词：岩石力学 翼裂纹 宏-细观损伤 应力-应变曲线 应力强度因子 

分 类 号：TU45[建筑科学—岩土工程]