Hyper-elastoplastic/damage modeling of rock with application to porous limestone

INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES

卷:143

Article

Bennett, K. C.^1,2  Borja, R. I.¹ 

[1] Stanford Univ, Dept Civil & Environm Engn, Stanford, CA 94305 USA

[2] Los Alamos Natl Lab, Div Theoret, Fluid Dynam & Solid Mech Grp, Los Alamos, NM 87545 USA

关键词: Rock;    Damage;    Microfracture;    Porosity;    Eshelby stress;    Drucker-Prager;   

DOI  :  10.1016/j.ijsolstr.2018.03.011

来源: Elsevier

【 摘 要 】

Relations between porosity, damage, and bulk plasticity are examined in the context of continuum damage and hyper-elastoplasticity of porous rocks. Attention is given to a thermodynamically consistent derivation of the damage evolution equations and their role in the constitutive equations, for which the Eshelby stress is found to be important. The provided phenomenological framework allows for volumetric damage associated with pore growth to be distinguished from the isochoric damage associated with distributed microcracks, and a novel Drucker-Prager/cap type material model that includes damage evolution is presented. The model is shown to capture well the hardening/softening behavior and pressure dependence of the so-called brittle-ductile transition by comparison with confined triaxial compression measurements from the literature. Non-linear finite element simulations are also provided of the prediction of damage within porous limestone around a horizontal borehole wall. (C) 2018 Elsevier Ltd. All rights reserved.

【 授权许可】

Free