Analysis of residual stresses in Al-Li repair welds and mitigation techniques

Abstract

In this paper, the recent results based on a comprehensive study on repair weld residual stresses are presented. Advanced finite element techniques were used to characterize the residual stress evolution in Al-Li alloy weldments, particularly under repair welding conditions. The present analysis procedures considered three-dimensional residual stress characteristics in the repair welds using a shell element model. Local residual stress details were analyzed by a generalized plane-strain model with prescribed translation and rotation conditions established from the global shell element model. Experimental residual stress measurements were conducted using X-ray diffraction methods. A good agreement between the finite element results and experimental measurements was obtained. Finally, a novel welding repair procedure (termed as a thermal stretching technique) was proposed to mitigate the weld residual stresses in repair.