Topology Optimization of Functionally‐Graded Lattice Structures Under Multiple Loading Conditions for Enhanced Stiffness and Robustness

ABSTRACT The topology optimization method of functionally graded lattice structures with multiple loading conditions is proposed to enhance both the structural stiffness and robustness. The conventional method for topology optimization of porous infill structures is extended to construct the functionally graded lattices, and the multiple loading conditions are introduced to formulate the optimization model with multiple objectives and multiple constraints. The multi‐objective optimization model is formulated into the minimization of maximum compliance with different loading conditions under the volume constraints. The gradient‐based optimization method is used to solve the optimization model, and the functionally graded lattice structures can be constructed efficiently and effectively. Numerical experiments prove that the proposed method performs better compared with conventional methods, and it will construct a connected and uniform lattice structure to improve both the stiffness and the robustness of the optimized structure with appropriate design domain and working conditions. To the best of our knowledge, this is the first work to verify the mechanical performance of an optimized functionally graded lattice structure manufactured from aluminum alloy, one of the most widely used metals in industry due to its excellent strength‐to‐weight ratio.