Industrial acceptanceof metal additive manufacturing (AM) is continuously rising along with its rapid development. As such, continuous research is needed to better understand the process and print characteristics to control and improve process parameters and as-built part quality. Dimensional tolerance, surface characteristics, and mechanical properties are all key qualities to assess for printer performance enhancement and repeatability. This paper presents results for physical and mechanical property inspections and testing on a designed test artifact for the benchmarking of 3D metal printers. The properties investigated include tensile strength, hardness, dimensional accuracy, roughness, and dross formation on overhanging features. Printed artifact results show similar anisotropic mechanical properties, with tensile strengths within the manufacturer-rated ranges. Dimensional XY-plane tolerances were within -0.18 to 0.18 mm and Z-axis tolerance within -0.10 to 0.10 mm for both printers. As-built roughness values were below manufacturer maximums for both Ra and Rz. The overhang performance was similar for both machines, with increasing dross for decreasing overhang angles.
Concurrent design facilities are used by space agencies and private organizations to conduct preliminary design activities in the development of space systems. Concurrent conceptual design is characterized by dynamic exchanges between a limited team of experts, defining the operational requirements, the systems architecture, the baseline design, and budgets for different resources. The results are a preliminary system baseline and product requirements that are used as inputs to the subsequent product development phases. A study of the input and output of this early phase of product development has confirmed that data generated in concurrent design studies essentially describes behavior with a limited set of information about the geometry. The geometry at this stage is mainly composed of functional configurations with geometric envelopes. Based on this behavioral information content, the authors have looked at the SAPPhIRE model of causality, initially developed by Chakrabarti, as a potential data structure to support this early phase of system development and possibly all phases of the product lifecycle. In this current work, we present two concrete examples of concurrent conceptual design data structures for space applications and show how such data structures could be represented within the extended SAPPhIRE model. When compared to current PLM data structures, the use of the extended SAPPhIRE model represents an alternative means of structuring information and communicating this information between stakeholders, providing better understanding of the relation between a system's structure, function and behavior. It also explicitly represents the links between subsystems and the iterative nature of the design process.
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