Determination of stress intensity factors for multi-material junctions

This study evaluates the junction-tip coordinates and the stress intensity factors (SIFs) of multi-material junctions using the image-correlation experiment and least-squares method. The major advantage of the proposed method is that the procedure is simple and systematic. First, complex displacement functions are deduced into a least-squares form, and then displacement fields from the image-correlation experiment are substituted into the least-squares equation to evaluate the SIFs. Compared with the SIFs from H-integrals using finite element results, the calculated least-squares SIFs are accurate if more than 10 eigenvalues are included. Furthermore, the least-squares SIFs are not sensitive to the maximum or minimum radius of the area from which data is included.