Experimental and analytical investigation on the coupled elastoplastic damage model of coal-rock: The investigation on damage model of coal-rock

Yundong Shou Yundong Shou,Jianwei Zhang Jianwei Zhang,Filippo Berto Filippo Berto

doi:10.3221/igf-esis.53.34

Abstract

In this paper, a novel coupled elastoplastic damage model for coal-rock is proposed to predict the deformation and potential disaster in coal mining. The conditions of small deformation and thermodynamic potential are considered, as well as the coupling of damage evolution process with the plastic deformation and the plastic hardening of coal-rock. Based on the theory of damage mechanics, the formulas of damage evolution, plastic yield and plastic potential of coal-rock are deduced theoretically. In addition, triaxial compression tests of coal-rock under the different confining stresses are conducted to reveal the law of deviatoric stress and strain. Based on the experimental data, the control parameters of the coupled elastoplastic damage model of coal-rock are determined. The theoretical results obtained from the coupled elastoplastic damage model for coal-rock agree well with those from the experiment. The proposed model is reasonable to predict the deformation of coal-rock.

Highlights

T wo types of inelastic behaviors generally exist in most rock materials: plastic deformation, related to sliding mechanisms inside the microstructure of rock matrix; and damage to rock materials, induced by spreading microcracks[1,2]
C ontinuum damage mechanics is investigated based on macro phenomenological theory, which deals with dissipative systems
Where k0 and 0 are respectively the bulk modulus and shear modulus of undamaged materials, and are the two parameters of coal-rock to present the effect of damage on the elastic mechanical properties of coal-rock

Summary

INTRODUCTION

T wo types of inelastic behaviors generally exist in most rock materials: plastic deformation, related to sliding mechanisms inside the microstructure of rock matrix; and damage to rock materials, induced by spreading microcracks[1,2]. This article proposes a novel coupled elastoplastic damage model for coal-rock to discuss the plastic deformation and induced damage found in coal mine. Triaxial compression tests of coal-rock under four confining stresses of 0MPa, 5 MPa, 10 MPa and 15 MPa are conducted.

Experimental results

RESULTS

CONCLUSION