Optimization of graded filleted lattice structures subject to yield and buckling constraints

To reduce the stress concentration and ensure structural safety for lattice structure designs, in this paper, a new optimization framework is developed optimal design of graded structures, innovatively integrating fillet designs as well yield buckling constraints. Both relative strut radii parameters are defined variables, BCC PC lattices. Numerical homogenization employed to characterize effective elastic constants stresses metamaterials. Metamaterial models represent relationships between metamaterial properties geometric variables. Yield constraints, based on modified Hill’s criterion Euler Johnson formulae respectively, functions A proposed with both constraints integrated. case study minimizing compliance Messerschmitt-Bolkow-Blohm beam, composed either or lattices, conducted. The guarantee optimized beams. beams filleted compared non-filleted lattices corresponding type, show reduced proportions subject high (σHill≥0.95) 6 ~ 7% reductions compliance.