Modeling the Tensile Behavior of Specimens Manufactured by the Selective Laser Melting Method Using Continuum Damage Mechanics Theory

Abstract

Selective laser melting (SLM) has been developed in recent decades. It is capable of manufacturing components with complex geometries. However, there is no reliable model to predict the failure of parts made by this technique. In this study, the continuum damage model (CDM) of Lemaitre and the Gurson-Tavergaard-Needleman (GTN) model are employed to simulate the tensile stress-strain behavior of SLM manufactured specimens and to study the specimen size effect. The numerical results are compared with experimental results of tensile tests of SLM manufactured specimens. It is shown that the two models appropriately simulate the tensile tests in the hardening part. However, when softening occurs, the modified CDM can better predict failure and size effect. It is also observed that the GTN model needs modifications of the parameters to be able to simulate the size dependency of the mechanical properties of the SLM manufactured parts, which is attributed to different initial values of porosity.