Effect of Mesh Density on the Estimation of Stress Intensity Factors Evaluated by Interaction Integral in the Experiment

The interaction integral is commonly utilized in numerical methods for evaluating the fracture parameter—stress intensity factor—and it can also be used in experiments. The purpose of this paper is to examine the effect of mesh density on the accuracy and convergence of the stress intensity factors evaluated in experiments using the interaction integral. The interaction integral is applied to the numerical displacement fields obtained by ABAQUS, and then the experimental displacement fields measured by digital image correlation are used to investigate the influence of mesh density on the stress intensity factor. The stress intensity factors estimated using the numerical displacement field and the experimental displacement field were compared at four mesh densities. The numerical results indicate that the higher the mesh density, the more accurate the stress intensity factor. However, there is a discrepancy between the experimental and numerical displacement fields. When using the interaction integration method to evaluate the stress intensity factor in experiments, too high a mesh density will reduce the accuracy and convergence of the stress intensity factor. This paper can provide a basic understanding for evaluating stress intensity factors using the interaction integral in experiments.