Analysis of some effective parameters on Stress Intensity factors in a Halfplane with vertical edge crack which is subjected to an Un-symmetrical tilted wedge by means of Digital Shearography

Determination of Stress Intensity Factor is one of the important parameters in fracture mechanics. One of the common geometries in evaluating of fracture mechanics problems is contact of tilted wedge with half plane that in this article Unsymmetrical tilted wedge geometry has been studied and digital Shearography as a non-destructive technique is applied to determine mixed mode stress intensity factors in a half plane with vertical edge crack which is subjected to an unsymmetrical tilted wedge. Optical setup with two in-plane illumination source is used to determine purposed strain variable and consequently obtain the mixed mode stress intensity factors as a result of applying linear elastic fracture mechanics (LEFM). The results of Shearography technique contains some fringes which contain the information needed to obtain the strain variables. To utilize the advantage of whole field Shearography and to minimize random experimental errors, the least square method is used to obtain SIF. In order to verify the obtained results accuracy, the experimental results were compared with the results of finite element method. The difference between two results is nearly 19%. The comparison of the experimental results and the numerical results proves the credibility and potential of this nondestructive method in measurement applications. Then the effect of crack size and gap of tilted wedge from crack tip on Stress Intensity Factors have been investigated. Finally it shown that in this problem Stress Intensity Factor in first mode of fracture is zero, so only second mode of fracture should be considered.