Micro-Mechanical Damage Model for Geomaterials Behavior Under Indentation

Gabsi, N. (Université de Tunis El Manar, Ecole Nationale d’Ingénieurs de Tunis) | Souissi, S. (Université de Tunis El Manar, Ecole Nationale d’Ingénieurs de Tunis) | Hamdi, E. (Université de Tunis El Manar, Ecole Nationale d’Ingénieurs de Tunis) | Karrech, A. (The University of Western Australia)

OnePetro 

ABSTRACT: Rock drilling efficiency is nowadays a challenge for resource engineers. The present paper focuses on the numerical investigation of rock mass behavior under indentation characterized by various physical and microstructural properties. The numerical model is implemented to study the effects of normal percussion in rock drilling conditions. The response is predicted numerically using the multi-purpose finite element software Abaqus. The study is meant to model a previous experimental investigation. A comparison between the numerical and experimental results of indentation is performed on a limestone rock sample. The proposed model consists of an axisymmetric deformable anisotropic and a heterogeneous block indented by a regular shaped rigid body. First, an elastic behavior of materials was adopted. Afterwards, a damage based numerical model was proposed in order to take into account the damage evolution in the rock sample. Moreover, a model parameter identification procedure was performed to calibrate all necessary parameters using the simple indentation test. It has been shown that numerical model can reproduce the elastic damaged behavior of rocks, as limestone, subjected to a simple indentation mechanism during rock drilling. These results confirm the experimental data and reveal that it could be used efficiently to simulate rock damage under similar loading conditions.

1 INTRODUCTION

One of the basic mechanisms in rock drilling or tunneling is the simple rock normal indentation. To improve drilling efficiency, it is necessary to assess the damage that rocks undergo during indentation, in order to optimize the drilling process.