(519b) Lightweight Polymer Lattices with Unconventional Mechanical Properties

Advances in 3D printing enable the fabrication of complex lattice structures with regular repeat units. These lattices use geometry to reduce weight and impart unconventional mechanical properties to the structure. The use of polymers introduces both time and temperature dependence to the response of the structure to mechanical loads. However, despite the prevalence of polymer base additive manufacturing techniques, limited research has been performed on polymer-based lattices. The investigations that have been performed are typically conducted under quasi-static, compressive loading conditions and at room temperature. Therefore, we investigate polymer-based lattices subjected to both thermal and mechanical loads. We use fused deposition modeling to fabricate planar lattice structures. The structures are tested in a custom test fixture mounted in an Instron tensile tester. Tension and compression tests are performed under both uniform and spatially varying thermal loads. In addition, we compare experimental results to predictions from finite element analysis. The understanding gained by this work provides insight into the mechanical behavior of polymer lattices in critical temperature regimes, around the glass transition temperature. Our work leads to the further development and application of these lattices to structures which require light weight and tunable mechanical properties.