Numerical fracture toughness assessment of two types of steel, AISI 420 and AISI 431, has been conducted in this paper. The J-integral is chosen as a criterion for fracture behaviour comparison of compact type (CT) specimens made of investigated materials. The values of J-integral are determined through a newly developed algorithm using finite element (FE) stress analysis results of numerically...

The well-known J integral of elastic fracture mechanics has been related to potential energy-release rate associated with crack extension and has proved to be of great value in fracture testing. In particular, the pathindependence of the J integral has been used to an advantage in performing acoustoelastic measurements along a closed contour surrounding a crack tip. In Mode I (opening mode) for...

This article revisits the formulation of J-integral in context hydraulic fracture mechanics. We demonstrate that use classical finite element models overestimates length fractures viscosity-dominated regime propagation. A analysis shows inaccurate numerical solution for fluid pressure is responsible loss accuracy J-integral. With this understanding, two novel contributions are presented. The fi...