An elastoplastic damage model for semi-brittle rocks

Abstract

A new elastoplastic damage model, based on experimental evidences and using a thermodynamic framework, is proposed for rock materials under a large range of stresses. The elastic and plastic properties are affected by induced damage, which leads to material softening behaviour. After formulation of the model and determination of its parameters, triaxial compression tests on sandstone are simulated to show the model's consistency. In order to describe progressive failure process due to onset of strain localization, the elastoplastic model is extended by including a non-local damage formulation. Three representative cases are studied. The numerical results verify the well-known fact that the elastoplastic non-local damage model avoids spurious mesh sensitivity and provides a reliable description of the growth of the damage zone and the failure process.

Keywords:

• Elastoplasticity
• Damage
• Strain localization
• Non-local damage
• Mesh sensitivity
• Sandstone
• Brittle rocks
• Rupture