Topology optimized design and validation of sandwich structures with pure-lattice/solid-lattice infill by additive manufacturing

Compared to standard structures with pure solid members, sandwich structures behave mechanical advantages in terms of strength-to-weight, stiffness-to-weight, energy absorption capabilities, yet lightweight potentials. Sandwich structures can be driven by both exterior layout and infill configuration design to improve structural performance while reduce the weight. In this paper, sandwich structures with pure-lattice / solid-lattice infill by additive manufacturing is systematically investigated in combination with topology optimized design and validation. The equivalent material properties of infill BCC and F₂BCC lattices are determined though finite element simulation. The newly developed sandwich structural topology optimization algorithm based on two-step density filtering is employed to obtain the conceptual designs with pure or hybrid infill. The topology optimized structures are fabricated by additive manufacturing, which are validated through three-point bending experiments and numerical simulations.