Numerical modeling of residual stresses in deposited metal layer with a moving laser energy source

A transient 3D process of metal layer solidification, formed with laser technology, is considered. The mathematical model is based on balance equation with visco-elasto-plastic rheological model and energy equation, taking into account diffusion, convective and radiation losses. Numerical solution is performed using Finite Element Method using an adaptive algorithm for constructing grid domain as a function of temperature gradient in an uncoupled formulation with the solution of discrete equations of non-stationary thermal conductivity and thermomechanics. The algorithm takes into account the movement of the heat source at a given speed by applying the technology of "killing", and subsequent "birthing", of parts of the material. Continuous deposition of material is carried out discretely, at each step of calculation corresponding to "birthing", of the next subdomain from the "killed", elements. Verification and validation of the numerical algorithm is performed. The influence of the unidirectional scan strategy of five layers of metal on von Mises residual stresses is shown.