Numerical simulation of forerunning fracture in saturated porous solids with hybrid FEM/Peridynamic model

TL;DR

This paper introduces a hybrid FEM and Peridynamic model to simulate forerunning fracture in saturated porous solids, validated through dynamic consolidation and fracture simulations under mechanical and fluid-driven conditions.

Contribution

It develops and validates a hybrid modeling approach combining FEM and Peridynamics for dynamic fracture prediction in saturated porous materials.

Findings

Successful simulation of forerunning fracture behavior in dry and saturated conditions.

Validation of the hybrid model with convergence studies.

Demonstration of fracture initiation under mechanical and fluid-driven loading.

Abstract

In this paper, a novel hybrid FEM and Peridynamic modeling approach proposed in Ni et al. (2020) is used to predict the dynamic solution of hydro-mechanical coupled problems. A modified staggered solution algorithm is adopted to solve the coupled system. A one-dimensional dynamic consolidation problem is solved first to validate the hybrid modeling approach, and both -convergence and -convergence studies are carried out to determine appropriate discretization parameters for the hybrid model. Thereafter, dynamic fracturing in a rectangular dry/fully saturated structure with a central initial crack is simulated both under mechanical loading and fluid-driven conditions. In the mechanical loading fracture case, fixed surface pressure is applied on the upper and lower surfaces of the initial crack near the central position to force its opening. In the fluid-driven fracture case, the fluid injection is operated at the centre of the initial crack with a fixed rate. Under the action of the applied external force and fluid injection, forerunning fracture behavior is observed both in the dry and saturated conditions.