Application of digital image correlation method for determination of mixed mode stress intensity factors in sharp notches

Abstract

In the present study, the applicability of the digital image correlation (DIC) method in deriving the notch stress intensity factors (NSIFs) is examined for sharp V-notched components under mixed mode I/II loading. For this purpose, in the first step, the analytical mixed mode stress and displacement fields around the sharp V-notches and the concept of NSIFs are presented. Then, in the second step, the V-notched diagonally loaded square plate (V-DLSP) specimen is chosen for performing the DIC experiments. Three different notch opening angles with four various combinations of mode I and mode II loadings are considered for the V-DLSP specimens tested. Subsequently, in the third step, the DIC method is employed to determine the experimental displacement fields in the V-DLSP samples. Finally, the displacement fields obtained experimentally from the DIC technique are fitted to the analytical displacement field to derive the NSIFs of sharp V-notches by using a numerical method called the over-deterministic method. Comparing the results obtained from DIC method with those obtained from the finite element (FE) analysis shows the effectiveness of DIC method in determining the stress field around sharp V-notches.