Using evolutionary algorithms to determine the residual stress profile across welds of age-hardenable aluminum alloys

Abstract

This paper presents an evolutionary based method for obtaining the unstressed lattice spacing, d0, required to calculate the residual stress state across a weld of an age-hardenable aluminum alloy, AA2024. Due to the agehardenable nature of this alloy, the d0 value depends on the heat treatment. In the case of welds, the heat treatment imposed by the welding operation is very dependent of the distance to the center of the joint, a factor which implies that a variation of d0 across the weld is expected. This limits the possibilities of conventional analytical methods to determine the required d0 profile. The interest of the paper is two-fold. First, to demonstrate that the application of an evolutionary algorithm solves a problem not addressed in the literature. Second, the analysis of the evolutionary process shows the robustness of the approximation allowing the obtention of solutions for different constraints of the material. Our results confirm the capacity of evolutionary computation to reach realistic solutions under three different scenarios of the initial conditions and the available experimental data.