Stress Field Analysis of V-Notches with Tip Cracks in a Polymer Material Using Digital Image Correlation

In this study, displacement field around v-notches of a poly methyl metha crylate (PMMA) specimen with tip cracks will be analyzed using digital image correlation technique. First intensity factor in combination with in-plane rigid body translations and rotation components will be determined by linear least squares fitting of the displacement field data to the corresponding relations among stress intensity factor and displacement field. The effect of v-notch angle on the results would be investigated. Experimental results will be compared with those obtained from finite element analysis. Good consistency is shown to exist between the results of two methods. The existence and a measure of a small region (corresponding to the plastic deformation zone in front of the crack tip) is demonstrated which should be excluded in data extraction for digital image correlation post-processing using linear elastic fracture mechanics relations.