Topology optimization of functionally-graded lattice structures with buckling constraints

• Published in: Computer methods in applied mechanics and engineering 2019-09, Vol.354, p.593-619
• Main Authors: Yi, Bing, Zhou, Yuqing, Yoon, Gil Ho, Saitou, Kazuhiro
• Format: Article
• Language: English
• Subjects: Buckling; Functionally gradient materials; Isotropic material; Lattice structure; Lattices (mathematics); Linear buckling; Mathematical analysis; Stiffness; Structural stability; Topology optimization; Variable infill
• ISSN: 0045-7825; 1879-2138
• DOI: 10.1016/j.cma.2019.05.055

Lattice structures have been widely studied due to their advantage of low stiffness-to-weight ratio or sometimes auxetic properties. This paper presents a topology optimization method for structures with functionally-graded infill lattices with buckling constraints, which minimizes compliance while ensuring a prescribed level of structural stability against buckling failures. To realize topologically-optimized structures filled with functionally-graded lattices, Helmholtz PDE-filter with a variable radius is applied on the density field in Solid Isotropic Material with Penalization (SIMP) method. Buckling load factors based on the linear buckling analysis is employed as buckling constraints. Numerical examples show that proposed method can generate stiff structures comparable to the ones by the SIMP, with functionally-graded infill lattices that improve the structural stability by avoiding long, slender features under compression. •A new method for topology optimization of functionally-graded lattice structure.•The buckling constraint is employed to improve the stability of infill lattice.•The method achieves high spatial lattice variations with guaranteed smooth connectivity.•The method generate stiff structure comparable to SIMP and with level of structural stability.