Experimental Measurement of Elastic-Plastic Fracture Parameters Using Digital Image Correlation Method

Abstract

This paper presents a complex experimental measurement of elastic-plastic fracture parameters such as J-integral, CTOD and J-resistance curve for ductile materials with single specimen test employing the Digital Image Correlation method. Main advantage of the approach is that it allows evaluation of the parameters directly from its definitions in contrast to current standardized measurements defined mostly by ASTM where the parameters are evaluated indirectly. Moreover, the method provides other useful information such as the extent and shape of a plastic zone in the vicinity of a crack tip. The presented method is employed in the case of thin-sheet aluminium alloy. Different approaches to determine a critical value of J-integral from experimental results; i.e., to determine the fracture toughness of the material are presented.