Evaluating Stress Triaxiality of High Strength Steel Using Stereo Image Correlation

Abstract

A method for evaluating the stress triaxiality of thin steel plate is studied. Three-dimensikonal displacements and the surface strains of high strength steel specimen are measured using a stereo image correlation method. The measurement is performed from both sides of the front and back to evaluate not only in-plane strains but also through-thickness strains. From the mesured strains, the principal stresses are calculated based on the total strain theory, and then the stress triaxiality is obtained. Experimental results show that the stress triaxiality history can be obtained by the proposed method.