Multi-Scale Approach of HCF Taking into Account Plasticity and Damage: Application to LPBF Materials

Abstract

Laser additive manufacturing enables economical production of complex lightweight structures. To realize the potential benefits of additive manufacturing technology in industrial applications, the fatigue performance of parts additively manufactured materials must be modelized. The aim of this paper is to present a new modeling approach combining plasticity and damage, and appropriate for as-built Laser-Powder Bed Fusion (LPBF) structures. The model presented is an extension of the Dang Van criterion, including damage, defined as porosity in the case of LPBF. Attention is focused on the integration of damage in a fatigue criterion using the concept of elastic shakedown. Finally, the case of 316L will illustrate the results of the model by fatigue tests with deterministic defects.