Determining 2D notch SIFs by the image-correlation method

This study evaluates the two-dimensional (2D) stress intensity factors (SIFs) of a sharp V-notch using the imagecorrelation experiment and least-square method for isotropic materials. First, the William's eigenfunction and complex displacement function approach are deduced into a least-square form, and then displacement fields from the image-correlation experiment are substituted into the least-square equation to evaluate the 2D SIFs. Compared with the SIFs from finite element and body force methods, the least-squares method can be used to calculate SIFs more accurately, if more than two displacement terms are included. The SIFs calculated from this least-squares method are not sensitive to the maximum or minimum radius of the area from which data is included. The major advantage of the proposed method is that the procedure is simple and systematic, so it can be applied to any finite element or experimental methods that obtain displacement fields.