Development of Adaptable Light Weighting Methods for Material Extrusion Processes

The material extrusion family of additive manufacturing processes, such as the fused deposition modelling (FDM) process, can be very expensive for component fabrication due to the long production times for large, thick walled, complex components, and the material costs. Introducing light weighting strategies could balance the required strength and material usage. As the material extrusion processes exhibit anisotropic mechanical characteristics, physical experimentation is required to calibrate simulation models. In this research, an easily programmable light-weighting methodology for a variety of internal structures is presented. A variety of advanced CAD tools are explored; however, using Rhinoceros^® with the Grasshopper^® graphical programming add-on, allows designers to visualize the internal structure geometry dynamically. Tensile and compression samples are quickly generated for a variety of interior configurations. Selected sample models and results, built using ABS material, are presented here. Unexpected failure occurred with the face center cubic void lattice for the compression tests. There are disjoint segments in the tool path, and unexpected voids are interspersed within the test specimen. It is found that the bead deposition path has an influence on the observed mechanical characteristics. Design constraints, and alternative internal structures are proposed, and modelled.