Novel procedure to determine actual stress-strain curves

Abstract

This paper presents a novel procedure for determining the actual stress- strain curves for undermatching rectangular welded joints made of martensitic armoured steel Armox 500T. The method is based on an analytical expression for true stress; digital image correlation (DIC) with two cameras, i.e. recording 3D deformations of samples; and finite element method (FEM) for stress state analysis of samples. Stresses obtained by dividing the force by the current cross-sectional area of the sample do not represent the actual stress occurring in the sample, because they do not take into account the stress concentration. In this paper we have analysed the stress concentration obtained numerically using Abaqus software in which the model's entered strain values are measured by DIC method.