Fatigue Life Characterization of Additively Manufactured Acrylic like Poly-Jet Printed Parts

Abstract

Application of additively manufactured components is gaining popularity in functional application. Several polymer-based additive manufacturing processes such as fused deposition modelling (FDM), selective laser sintering (SLS), stereolithography apparatus (SLA) and poly-jet printing to name a few cater to automotive to medical applications. Reliability in service of these components has to be ascertained for using them for functional application. The components made from additive manufacturing have inherent anisotropy due to the process characteristics such as build orientation and laser scanning/deposition tool paths. Literature reports fatigue life characterization mostly in FDM parts. In this work, a fatigue life analysis was carried out on components manufactured by poly-jet printed parts. Also, two build orientations were used to study the effect of this process parameter on the tensile strength and fatigue life. Other process parameters such as layer thickness, finishing type and polymer material were kept constant. A standard test specimen as per ASTM standard D7791–12 was prepared using Stratasys^® Eden 350 V^™ poly-jet printer using Veroclear 720^™ material in two build orientations. The specimens were tested for tensile test and tensile–tensile fatigue cycles to failure at different stress levels. The test results were analysed to understand the fatigue life characteristics, and it was found that the process parameter variation has significant effect on the part strength (tensile) and reliability (fatigue failure). The fractured surface was analysed using SEM images to corroborate the inferences from test results.