Performance impacts of 3d slicers on additively manufactured composite joints

Topology optimization (TO) combined with composites additive manufacturing (AM) enables design of skeletal structures that present opportunities for weight savings in aerospace structures. Of critical importance in these structures are intersecting elements, or joints, that, if improperly designed, can be origin points for structural failure. This study simplifies TO joints to 4-member AM x-joints and investigates the performance impact of the slicing software and infill pattern on the joint. A mechanical test method was developed to evaluate x-joints in a two phase study. Phase I leveraged fused filament fabrication (FFF) of neat PLA in a screening study that sampled the available design space. Using the data collected in phase I, phase II produced additively manufactured composites via direct ink writing (DIW). Ultimately, slicer and infill patterns were recommended for the creation of AM composite joints that demonstrate high stiffness, repeatable maximum stress, and progressive damage. Preliminary mosaic style numerical simulations which accurately predict damage and material response were also completed.