ABSTRACT:

Fracture mechanics can be applied to many engineering fields including civil and mining engineering, where drilling, excavation, fragmentation and cutting of rocks are closely related to the strength, stability and fracture of rock materials and structures. This study presents an application of fracture mechanics to determine the effect of dimensions on mixed-mode fracture properties of rocks by using the numerical analyses. Using the finite-element results, correction factors were applied to the specimens and a polynomial fit was proposed to evaluate the stress intensity factors of a modified version of Arcan specimen with a crack subjected to mixed mode loading. The finite element analyses of bonded joints were also studied for different thickness and crack length. The mixed-mode fracture toughness tests were carried out by using rectangular specimens over a wide range of loading angles. Using the finite element results, non-dimensional stress intensity factors applied to the rectangular fracture specimen. It is also shown that when the ratio of crack length to specimen thickness (a/w) is increased, the stress intensity factors in mode-I and II are raising too. But this growth is tangible in mode-I. On the other hand the proportion of loading in mode-I and II between 60 and 70 degree is same.

1. INTRODUCTION

This investigation seeks to extend understanding of the rock fracture behavior of a type of limestone under mixed-mode loading conditions through numerical methods. The main objective of this study is to determine the effect of dimensions on mixed-mode fracture properties of rocks by using the numerical analyses. Using finite element results, correction factorswere applied to the limestone specimen and a third order polynomial fit is proposed to evaluate the stress intensity factors of a modified version of the Arcan specimen with a crack subjected to mixed-mode loading conditions.

This content is only available via PDF.
You can access this article if you purchase or spend a download.