TAILORED ENERGY ABSORPTION FOR 3D PRINTED MULTI-MATERIAL CELLULAR STRUCTURES USING ABS AND TPU

Advances in multi-material 3D printing technologies are enabling the construction of advantageous engineering structures for diverse applications. Multi-material printing allows the combination of contrasting engineering materials in a single part to gain synergistic performance increases. Cellular structure such as honeycomb structures provide high-energy absorption to weights ratio that could benefit through multi-material strategies for tailored responses in applications such as design of helmets and prosthetics. In this study, we investigate the compressive response and the energy absorption for combinations of acrylonitrile butadiene styrene (ABS) and thermoplastic polyurethane (TPU) printed lattices. Results demonstrate energy absorption increases from pure TPU samples of 2.18kN.mm in a non-linear fashion to pure ABS samples of 11.47kN.mm as bands of TPU are added to ABS. Splitting a single band of TPU into multiple bands with the same total thickness changes the behavior of first and second peak before densification. Testing with in-plane loading demonstrated more similar behavior among the differently designed multi-material lattices, with collapsing occurring with sequential failures of unit cell rows. These results demonstrate the feasibility in constructing multi-material lattice systems with ABS and TPU combinations, while highlighting their benefits for enabling controlled energy absorption and deformation responses based on designed material combinations.