An Investigation of the Fatigue Strength of Multiple Cellular Structures Fabricated by Electron Beam Powder Bed Fusion Additive Manufacturing Process

Abstract

In this study multiple cellular structures, including the re-entrant auxetic, the octet-truss, and the BCC lattice, were evaluated for their relative performance of fatigue strength under compression-compression cyclic loading. Various design variations with different dimensions were fabricated via electron beam powder bed fusion (EB-PBF) additive manufacturing (AM) process and experimentally tested. Initial S-N based fatigue strength characterization with the BCC lattice shows significantly decreased fatigue strength of the cellular parts compared to the solid samples. Cross-design comparison were consequently carried out using constant maximum stress ratio level. The results indicate that the fatigue characteristics of the EB-PBF cellular structures are not only dependent on their topology types but also their geometry dimensions.