A simplified modelling of hydraulic fractures in elasto-plastic materials

TL;DR

This paper introduces a simplified model for hydraulic fracture propagation in elasto-plastic materials, incorporating a new stress redistribution approach and a plasticity-dependent crack propagation condition, applicable for moderate plastic deformations.

Contribution

It presents a novel simplified model that captures plastic deformation effects near the crack tip in hydraulic fractures, reducing computational complexity.

Findings

Plastic deformation causes crack-tip shielding.

The model accurately predicts fracture behavior with moderate plasticity.

Plasticity effects can be approximated without full elasto-plastic modeling.

Abstract

In this paper the problem of a plane strain hydraulic fracture propagating in an elasto-plastic material is analyzed. A new stress redistribution model for the proximity of the fracture tip is formulated and a resulting plasticity-dependent crack propagation condition is introduced. A modified variant of the KGD problem that accounts for the plastic deformations in the near-tip zone only is proposed. It is demonstrated that this model can be a credible substitute for the full elasto-plastic hydraulic fracture problem in the case of moderate plastic deformation. The crack-tip shielding effect introduced by the plastic deformation is quantified.