Equivalent orthotropic properties of periodic honeycomb structure: strain-energy approach and homogenization

The primary objective of the proposed work was to present a theoretical and computational procedure to predict the effective elastic properties of a periodic honeycomb structure. In the theoretical framework, the effective orthotropic elastic properties were determined using the strain-energy approach. Whereas in the computational procedure, a homogenization technique based on the finite element (FE) method in conjunction with periodic boundary conditions (PBCs) was used to determine the equivalent properties of the honeycomb core. A suitable representative cell element (RCE) was chosen for this purpose. The computed effective elastic properties were compared with those obtained from the strain-energy approach, and the reference results were in good agreement with each other. Subsequently, the obtained elastic properties were used as material parameters of the sandwich structure comprising homogenized core structure and the face sheets for the FE analysis of the 3-point bend test (3PBT) of a sandwich structure, edge-compression test, and buckling problems. The results were compared with those obtained from the direct FE simulation of the honeycomb core structure. The comparison showed that the results were satisfactory, with a significant reduction in the computational time. Finally, the modal analysis was performed to reaffirm the efficiency of the presented procedure.