Design and optimization of solid lattice hybrid structures fabricated by additive manufacturing

Additive Manufacturing (AM) has largely relieved the design freedom of functional parts. Topology optimization has been widely used to design lightweight structures fabricated by AM. In this paper, a general design method is proposed to design solid lattice hybrid structures. An optimization algorithm is used in this method that can generate a functionally graded heterogeneous lattice structure connecting the solid part. The manufacturability can be improved due to the lattice structure supporting the overhangs. The selection of the lattice topology and the generation of the solid-lattice space are explained in detail. A hybrid element model is used to simulate the mechanical performance and optimize the material distribution of the lattice structure. To validate the design theory and the advantage of the hybrid structure, a three-point bending beam is designed by the proposed method and the existing methods. Both the simulation result and the experimental result show that the hybrid structure has a higher stiffness, yield strength, and critical buckling load than the pure solid structure and the pure lattice structure.