Equivalent homogenization design method for stretching-bending hybrid lattice structures

An efficient and accurate equivalent design method for hybrid lattice structures is proposed. First, the equivalent mechanical properties of the lattice structures are calculated, including the equivalent elastic modulus, shear modulus, and Poisson's ratio. We construct an effective and simple stretching-bending hybrid lattice structure, which uses two types of lattice structures: stretching-dominated lattice structure and bending-dominated lattice structure. The optimal material density distributions are obtained via topological optimization by taking three-point bending beams and L-shaped beams as examples. The optimized stretching-bending hybrid lattice structures are designed based on the equivalent properties of the lattice structures. The same relative density uniform lattice structure is constructed while being compared with the stretching-bending hybrid lattice structure. The corresponding equivalent homogenization model and accurate beam model are established for comparison and verification by finite element analysis. Results show that the hybrid lattice structure has higher stiffness than the uniform lattice structure with the same relative density. The equivalent homogenized model of a hybrid lattice structure can effectively characterize the mechanical properties of the structure and improve design efficiency.