Design optimization of geometry and non-uniform arrangement for honeycomb cells considering size effect

To improve the strength and stiffness of a honeycomb core as well as the accuracy of equivalent elastic modulus calculation, a new optimization method with the consideration of size effect is developed for the non-uniform arrangement of cells with variable geometry. The analytical relations between the size and shape control factors and equivalent elastic constants are established using the energy method. The stiffness matrixes of substructures formed by uniform division of the honeycomb core are calculated using the finite element method. The static condensation technique is adopted to derive the stiffness matrixes of super-elements, and the global stiffness matrix of the honeycomb core is obtained through assembly. A multi-objective optimization model taking the size and shape control factors as design variables is solved using the improved particle swarm optimization algorithm to maximize the equivalent elastic moduli and minimize the structural deformation. The results are compared with those from the collaborative technology of MATLAB and ANSYS, and the static, modal and harmonic response analysis are performed on original and optimized honeycomb cores. Significant improvements of the structural performance are achieved in this process, confirming that the developed method constitutes a valuable tool for optimizing the geometry and arrangement of honeycomb cells.