Topology optimization of shell-infill structures considering buckling constraint

Abstract

This paper presents a density-based topology optimization approach to design shell structures and non-uniform infills concurrently for efficient stiffness and stability. The buckling load factors are computed by linearized buckling analysis, the lower bound of which is constrained to ensure the structural stability. Besides, an overhang constraint and a two-field-formulation-based length scale control approach are utilized, ensuring that the optimized structures satisfy the geometry requirements for additive manufacturing(AM). By solving the topology optimization problem, the shell geometry and the infill layout can reach a desirable match such that the structural stability is ensured and the stiffness is also optimized. Numerical examples show that the stability of the shell-infill structure optimized by the proposed approach can be increased significantly at the cost of a slight degradation of stiffness comparing to that optimized without the buckling constraint.