Thermal stresses in growing thermoviscoelastic cylinder and their evolution in the course of selective laser melting processing

Abstract

The evolution in time of stresses and strains in a solid during its manufacturing through selective laser melting (SLM) process is studied. The technological technique, which allows to reduce the intensity of internal and residual stresses is proposed and theoretically grounded. The basic concept of the technique is that the additional in-homogeneous inductive heating in the vicinity of the growing boundary is applied in the processing. The term "growing boundary" refers to the part of the boundary, on which the additional melted material is added. The evolutionary problem for a growing thermoelastic body is considered in approach of thermal stresses (for slow additive processes) and in the approach of full coupled thermoelasticity (for fast processing). The time depend distribution of internal stresses and their residual counterparts has been evaluated in analytical form in the case of model cylindrical problem. The analysis of the influence of frequency and amplitude of electromagnetic induction as well as viscoelastic properties of heated material being added has been carried out. The results are analyzed numerically for Titanium and Copper materials.