NUMERICAL GRAPHICAL IMPLEMENTATION OF MAXIMUM STRAIN-ENERGY DENSITY CRITERION

In this paper a numerical/graphical method is developed to establish the initial angle of crack propagation and the associated fracture load for a crack in a mixed mode. This method incorporates the maximum dilatational strain energy density criterion (SED). The resultant stresses, obtained by the finite element method (FEM) are used to establish the distribution of the distortional component of SED (i.e: Von-Mises elastic-plastic boundary) around the crack tip. The angle at which the crack propagates is the angle where the dilatational component of SED attains a maximum. It is also postulated that the fracture will occur if the distance from the crack tip to the point of the maximum dilatational SED exceeds a critical distance, with the critical distance being a material constant. The predicted results are compared to the measured results (both experimental, and analytical) of other researchers.