Residual stress modelling by experimental measurements and finite element analysis

Abstract

The paper describes an experimental-numerical technique for modelling plane residual stress fields with application to steel slabs containing laser welds of different geometry. This technique is based on the analysis of the strain measured by several small-size strain gauges as a function of the depth of a narrow slot which was cut in the slab itself in small increments. This information was combined with sensitivity coefficients obtained via finite element models in order to derive initial strain distributions for the welded plates. These distributions allowed a prediction to be made of the residual stresses acting in generic bodies extracted from the original plates. The stress fields predicted for square specimens cut from the slabs were then compared with the measured values, showing a fairly good agreement.