Degradation mechanism of rock under impact loadings by integrated investigation on crack and damage development

作     者：周子龙 江益辉 邹洋 翁磊 ZHOU Zi-long,;JIANG Yi-hui;ZOU Yang;WONG Lei

作者机构：School of Resources and Safety Engineering Central South University 

出 版 物：《Journal of Central South University》 (中南大学学报（英文版）)

年 卷 期：2014年第21卷第12期

页      面：4646-4652页

核心收录：

学科分类：0810[工学-信息与通信工程] 0806[工学-冶金工程] 08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 0812[工学-计算机科学与技术（可授工学、理学学位）] 080102[工学-固体力学] 0801[工学-力学（可授工学、理学学位）] 

基　　金：Projects(51274254,51322403)supported by the National Natural Science Foundation of China Project(NCET-11-0528)supported by theProgram for New Century Excellent Talents in University,China Project(2013SK2011)supported by Hunan Province Science andTechnology Plan,China 

主　　题：impact loading dynamic failure particle flow code crack damage 

摘      要：Failure of rock under impact loadings involves complex micro-fracturing and progressive damage. Strength increase and splitting failure have been observed during dynamic tests of rock materials. However, the failure mechanism still remains unclear. In this work, based on laboratory tests, numerical simulations with the particle flow code(PFC) were carried out to reproduce the micro-fracturing process of granite specimens. Shear and tensile cracks were both recorded to investigate the failure mode of rocks under different loading conditions. At the same time, a dynamic damage model based on the Weibull distribution was established to predict the deformation and degradation behavior of specimens. It is found that micro-cracks play important roles in controlling the dynamic deformation and failure process of rock under impact loadings. The sharp increase in the number of cracks may be the reason for the strength increase of rock under high strain rates. Tensile cracks tend to be the key reason for splitting failure of specimens. Numerical simulation of crack propagation by PFC can give vivid description of the failure process. However, it is not enough for evaluation of material degradation. The dynamic damage model is able to predict the stress-strain relationship of specimens reasonably well, and can be used to explain the degradation of specimens under impact loadings at macro-scale. Crack and damage can describe material degradation at different scales and can be used together to reveal the failure mechanism of rocks.