Microstructure Based Simulations to Identify failure Mechanisms in Additively Manufactured Metallic Components
Technical Report,02 Nov 2015,02 Nov 2018
University Of California, Santa Barbara Santa Barbara United States
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A combined experimental- and simulation-based approach for electron beam melted Ti-6Al-4V strut-based structures was used to identify printing-related features that impact response and to develop highly-efficient, low-dimension models that can incorporate such features. Testing and modelling were completed for sub-elements of a complex lattice primitives, consisting of struts, strut intersections or nodes and cells consisting of multiple nodes. Mechanical testing and characterization illustrated that strut size, shape and mechanical response depend on the orientation of the strut relative to the build direction. Testing of node primitives and cells revealed that the truss structures were generally more compliant and weaker than expected from elementary truss models conversely, they exhibit greater load-carrying capacity beyond peak loads. Beam-based models were adapted to account for the plastic localization near defects and within nodes by using additional beam elements. Fully resolved two-dimensional FEA of strut intersections illustrated that the transition from node yielding to widespread strut yielding is controlled by the spread of plastic zones across the node. This behavior can be captured using beam elements that form a box whose corners connect to strut axes. Fully resolved 2D FEA and beam-based models were used to represent structures with multiple nodes and defects.
- Manufacturing and Industrial Engineering and Control of Production Systems