Plastic buckling of metallic honeycombs

An experimental program was conducted to investigate the buckling phenomena of metallic honeycomb cellular structures when they are subjected to axial loading applied quasi-statically. Six types of honeycomb specimens, made of 5052 and 5056 aluminums, were employed. It was found that both of the bare compressive and crush strengths of these cellular structures were significantly affected by the cell width and the strength of the material composed of the honeycomb, and, to some extent, the height of the specimens. In order to obtain the optimal energy absorption capability per unit density for the cellular structures, it is suggested to select the honeycomb structure made by the material with high strength and with small cell width but short core height. It is also interesting to find that the energy absorption capability was enhanced by the increase of the loading rate. On the other hand, the previously published theoretical and experimental data were found to significantly underestimate the results, and the theoretical model was found to be too oversimplified to represent the actual plastic buckling mechanisms of metallic honeycomb structures.