Qualification of additively manufactured aerospace brackets: A comparison between thermoelastic stress analysis and theoretical results

Abstract

Metal brackets made in titanium based-alloys are one of the most diffused case studies in the field of Additive Manufacturing (AM) technologies: the current generation of satellites relies on metal brackets to serve as a link between the body of the satellite and the reflectors and feeder facilities mounted at its upper end. In this scenario, one of the main focal points is the qualification of the 3D printed-products, including both the characterization of the micro/macro-structure of the component, and the definition of its mechanical behavior. Despite the high presence, in literature, of works dealing with the detection of defects in the structure, no dissertation can be found about stress analysis on the actual component, and this is what this paper focuses on. This topic is crucial because some morphological or dimensional differences between the nominal (CAD) structure and the manufactured one could lead to non-predicted stress concentrations at the end. We performed a feasibility study of the Thermoelastic Stress Analysis on a titanium based-alloy space bracket, made by Electron Beam Melting (EBM). The success of our study, plus a Non-Destructive Dimensional Measurement (triangulation system for reverse engineering) could enable the classical topology optimization processes to be implemented a posteriori, thus providing an additional time and cost saving.