Numerical and Experimental Investigation of Compressive Properties of Egg Box Cores of Green Sandwich Panels

In this study, the compression behavior of cardboard Egg Box cores with various stacking sequences used in sandwich structures are investigated both experimentally and numerically. A critical requirement of the design is that the structure is compatible with the environment (biodegradable), and its properties have been investigated through compression and tension testing. This study aims to investigate the bending characteristic of cardboard egg box to reduce the use of chemicals and get benefits of this shape in construction of biodegradable sandwich panels. Egg boxes were chosen as the core material for sandwich structures due to their mechanical strength, excellent insulation properties, and strength. Also, the core shape in various stacking sequences were model in ABAQUS FE code to simulate the behavior of the egg box core in bending. The results showed that the surrounding edges of the core crushed and the truncated top region compressed. The increase in thickness of the egg boxes directly affected the compression properties. By doubling the thickness of the layers, the amount of energy absorbed by the core increased by more than 110%. By comparison of various stacking sequence of the cores, the one with double layers of the egg boxes overlapped, showed an increase of 32% in stiffness, 64% in energy absorption, and 59% in strength.