A micromechanics-based fractional frictional damage model for quasi-brittle rocks

2021 ◽  
Vol 139 ◽  
pp. 104391
Author(s):  
Peng-Fei Qu ◽  
Qi-Zhi Zhu ◽  
Lun-Yang Zhao ◽  
Ya-Jun Cao
Keyword(s):  
Damage Model ◽  
Brittle Rocks

scholarly journals A coupled elastoplastic damage model for brittle rocks: elastoplastic damage model for brittle rocks

2020 ◽  
Vol 14 (53) ◽  
pp. 446-456
Author(s):  
Zheng Li ◽  
Yundong Shou ◽  
Deping Guo ◽  
Filippo Berto
Keyword(s):  
Damage Model ◽  
Brittle Rocks ◽  
Elastoplastic Damage

Coupling Analysis between Stress Induced Anisotropic Damage and Permeability Variation in Brittle Rocks

2007 ◽  
Vol 340-341 ◽  
pp. 1133-1138 ◽  
Author(s):  
Hui Zhou ◽  
Jian Fu Shao ◽  
Xia Ting Feng ◽  
Da Wei Hu
Keyword(s):  
Damage Model ◽  
Coupling Model ◽  
Mechanical Analysis ◽  
Effective Porosity ◽  
Anisotropic Damage ◽  
Permeability Evolution ◽  
Coupling Analysis ◽  
Brittle Rocks ◽  
Permeability Variation ◽  
Set Up

In this paper, a coupling constitutive model is proposed for anisotropic damage and permeability variation in brittle rocks before cracks fully coalesce. In this coupling model, an anisotropic damage model is employed to perform the mechanical analysis, and a statistical penetration model is set up to describe the effective porosity and permeability evolution in brittle rocks. For the coupling analysis, anisotropic damage model offers statistical penetration model the crack length in various directions, and statistical penetration model inversely provides anisotropic damage model with permeability of rock for coupling hydro-mechanical analysis. The proposed coupling model is applied to Lac du Bonnet granite, and generally a good agreement is obtained between numerical simulations and experimental data.

A MULTIPHASE ANALYSIS FOR ENVIRONMENTAL IMPACT ASSESSMENT WITH θ-STOCK FINITE ELEMENT PROGRAM

2010 ◽  
Vol 02 (01n02) ◽  
pp. 23-68 ◽  
Author(s):  
B. GATMIRI ◽  
S. HEMMATI ◽  
C. ARSON ◽  
E. AMIRZEHNI
Keyword(s):  
Finite Element ◽  
Thermal Loading ◽  
Damage Model ◽  
Degree Of Saturation ◽  
State Variables ◽  
Field Equations ◽  
Finite Element Program ◽  
Independent State ◽  
Brittle Rocks ◽  
Element Program

In the THM modeling of multiphase medium, the coupling effects of skeleton, suction, and temperature have been integrated via the concept of state surfaces of void ratio and degree of saturation. Based on proposed formulation, a fully coupled numerical model for the behavior of soil deformation, water flow, air flow, heat flow in unsaturated soil has been developed and integrated in a finite element code θ-Stock by the first author. This program is conceived with this idea that it will be able to analyze the response of a soil in different states of humidity to mechanical, thermal loading, and also damage phenomena. Damage model is dedicated to unsaturated brittle rocks. It mixes phenomenological and micromechanical concepts and is formulated based on the use of independent state variables. The expression of the liquid permeability is modified in order to represent the influence of fracturing on interstitial fluid flows. The final matrix form of established field equations of the proposed model for unsaturated case has been encoded for this particular purpose, in a finite element program which had been developed for dry and saturated soils previously.

scholarly journals A Micromechanical Anisotropic Damage Model for Brittle Rocks With Non-Associated Plastic Flow Rule Under True Triaxial Compressive Stresses

2021 ◽  
Vol 9 ◽  
Author(s):  
Shuangshuang Yuan ◽  
Qizhi Zhu ◽  
Wanlu Zhang ◽  
Jin Zhang ◽  
Lunyang Zhao
Keyword(s):  
Plastic Flow ◽  
Damage Model ◽  
Local Stress ◽  
Inclusion Problem ◽  
Flow Rule ◽  
Model Parameters ◽  
Anisotropic Damage ◽  
True Triaxial ◽  
Brittle Rocks ◽  
Plastic Flow Rule

A micromechanical anisotropic damage model with a non-associated plastic flow rule is developed for describing the true triaxial behaviors of brittle rocks. We combine the Eshelby’s solution to the inclusion problem with the framework of irreversible thermodynamics. The main dissipative mechanisms of inelastic deformation due to the frictional sliding and damage by microcrack propagation are strongly coupled to each other. A Coulomb-type friction criterion is formulated in terms of the local stress applied onto the microcracks as the yielding function. The back-stress term contained in this local stress plays a critical role in describing the material’s hardening/softening behaviors. With a non-associated flow rule, a potential function is involved. Some analytical analysis of the non-associated micromechanical anisotropic damage model are conducted, which are useful for the model parameters calibration. The proposed model is used to simulate the laboratory tests on Westerly granite under true triaxial stresses. Comparing the numerical simulation results provided by the models with associated/non-associated plastic flow rule and experimental results, it is clear that the proposed non-associated model gives a better prediction than the previous associated model.

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