Experimental and computational analysis of additively manufactured tensile specimens: Assessment of localized-cooling rate and ductile fracture using the Gurson– Tvergaard–Needleman damage model

Abstract

The present contribution addresses the micromechanical and thermal analysis of directed energy deposition-manufactured, stainless steel 316L components by utilizing experimental and numerical analyses. It has been established that a combination of controlling process parameters, manufacturing environment and microstructural anisotropies could adversely affect the quality of as-deposited parts. Among other factors, the shape, size, and distribution of the microvoids and porosities could, to some extent, have deteriorating effects on the mechanical properties of the additively manufactured components. In this work, the micromechanically motivated Gurson–Tvergaard–Needleman damage model is utilized and the performance of the model is evaluated by observing the damage accumulation in the loaded additively manufactured specimens. By relying to the laboratory-based material data and fractographic imagery from nonstandard tensile testing on fabricated samples in different building directions, numerical model predictions are found to be in a good agreement with the experimental observations. Furthermore, by resorting to the finite element software capabilities, the thermal analyses are carried out on the manufactured cube component and the influence of the process parameters on the temperature distribution is revealed.