MICROMECHANICS DAMAGE MODELING OF BRITTLE ROCK FAILURE PROCESSES UNDER COMPRESSION

2013 ◽  
Vol 10 (06) ◽  
pp. 1350034 ◽  
Author(s):  
JIAWEN ZHOU ◽  
XINGGUO YANG ◽  
ZHAOHUI YANG ◽  
HONGTAO LI ◽  
HONGWEI ZHOU

This paper presents a numerical simulation method for the brittle rock failure process under compression, by combining the finite element method with micromechanics damage theory. When considering the rock as a homogeneous material, the initial elastic constant of each computational element is the same, but the microcrack distribution in the rock follows a statistical distribution. Consequently, in the loading process, microcrack propagation in each element is different, leading to an inhomogeneous distribution of changes in elastic constant. Under increased loading, this distribution will ultimately be reflected in the macro-failure mode of the rock. To investigate the macromechanics of the rock failure process, the damage variables and effective elastic constants are used to reflect the propagation of microcracks, thus coupling the micromechanics and macromechanics of the rock failure process. Finally, the paper demonstrates the numerical simulation method by simulating the failure of sandstone; these computational results show that the method performs well in simulating the mechanical characteristics of the brittle rock failure process.

2019 ◽  
Vol 83 (sp1) ◽  
pp. 251
Author(s):  
Runcheng Xie ◽  
Chenggong Zhang ◽  
Shaoke Feng ◽  
Yongming Duan ◽  
Jun Chen ◽  
...  

2007 ◽  
Vol 353-358 ◽  
pp. 933-936 ◽  
Author(s):  
Deng Pan Qiao ◽  
Ya Ning Sun ◽  
Shu Hong Wang ◽  
Juan Xia Zhang

The failure of rock mass under loading is resulting from preexisting flaws, such as cracks, pores and other defects. However, the propagation and coalescence mechanism among multi-group cracks is still a puzzle, especially to the engineering rocks in site. In this study, the failure of rock samples with two groups of preexisting parallel cracks under the axial load were numerically investigated by the Rock Failure Process Analysis code (RFPA) from a mechanics point of view. The simulated results reproduce the rock failure process: at the first loading stage, the particle is stressed and energy is stored as elastic strain energy with a few randomly isolated fractures. As the load increases, the isolated fractures are localized to form a macroscopic crack. At the peak load, the isolated fractures unstably propagate in a direction parallel to the loading direction following tortuous paths and with numerous crack branches. Finally, the major crack passes through the rock sample and several coarse progeny cracks are formed. Moreover, in the vicinity of the contacting zone the local crushing is always induced to cause fines. On the base of the simulated results, it is found that the dominant breakage mechanisms are catastrophic splitting and progressive crushing. It is pointed out that the particle breakage behavior strongly depends on the heterogeneous material property, the irregular shape and size, and the various loading conditions. Because of heterogeneity, the crack propagates in tortuous path and crack branching becomes a usual phenomenon. The failure process of rock sample demonstrated that due to the high stress concentration at the cracks tip or some weaker strength elements which are not on the cracks surface initiate some micro-fractures, those cracks and fractures may gradually become larger and larger, more and more with the progress of loading so that join into the branch cracks leading to the rock failure in the end. Not only did the output of the numerical simulation study compare well with the experiment results, but also the further insights of the mechanism of cracks propagation and coalescence process in rock mass were obtained.


2017 ◽  
Vol 322 ◽  
pp. 301-312 ◽  
Author(s):  
Susumu Yamashita ◽  
Takuya Ina ◽  
Yasuhiro Idomura ◽  
Hiroyuki Yoshida

2012 ◽  
Vol 229-231 ◽  
pp. 55-58
Author(s):  
Jun Fan

To obtain the know-how of the deficiency for the filling capability, taking Ti75 alloy as the research object, at the same height of reducing, strain rates during forming as the control objective, the finite element numerical simulation method was used to simulate the hot compression with DEFORM-3D, analyzing the effect of the strain rates on the distribution of strain and stress.


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