Phase Field Characterization of Rock Fractures in Brazilian Splitting Test Specimens Containing Voids and Inclusions

TL;DR

This study uses phase field modeling within finite element analysis to investigate how voids and inclusions affect fracture patterns and strength in Brazilian rock splitting tests, enhancing understanding of inhomogeneous rock behavior.

Contribution

It introduces a phase field model approach to simulate fracture mechanisms in rocks with voids and inclusions during Brazilian tests, advancing numerical characterization methods.

Findings

Phase field simulations reproduce experimental fracture phenomena.

Void and inclusion characteristics significantly influence fracture patterns.

The approach enhances understanding of inhomogeneous rock deformation.

Abstract

The Brazilian splitting test is a widely used testing procedure for characterizing the tensile strength of natural rock or rock-like material due to the fact. However, the results of Brazilian tests on specimens with naturally existing voids and inclusions are strongly influenced by size effects and boundary conditions, while numerical modeling can assist in explaining and understanding the mechanisms. On the other hand, the potential of utilizing Brazilian test to characterize inhomogeneous deformation of rock samples with voids and inclusions of dissimilar materials still awaits to be explored. In the present study, fracture mechanisms in Brazilian discs with circular voids and filled inclusions are investigated by using the phase field model (PFM). The PFM is implemented within the framework of finite element method to study the influence of diameter, eccentricity, and quantity of the voids and inclusions on the fracture patterns and stress-strain curves. The phase field simulations can reproduce previous experimental phenomena and furthermore it deepens the understanding of the influence of inclusion and voids on the fracture pattern, overall strength and deformation behavior of inhomogeneous rock. The findings in the study highlight the potential of characterizing inhomogeneous rock through combining Brazilian tests and numerical modeling.