A study on the static and dynamic loading of the foam filled metal hexagonal honeycomb – Theoretical and experimental

A theoretical model for determination of the mean crushing strength of the foam filled metal hexagonal honeycomb under quasi-static loading has been presented through implementing the energy method and considering the interaction effects between honeycomb cell walls and filler foam. Afterwards, by developing the static model to the dynamic state, a simple theoretical model for determination of the required initial velocity of the impactor has been proposed, such that the desired folding length in these energy absorbers under low velocity impact loading is created. Verification of the presented theoretical models has been performed by experimental results obtained from experiments on several kinds of foam filled honeycomb with various minor diameters, thicknesses of the cell walls and foam filler densities. In addition, the experimental data show that the mean crushing stress of the foam filled honeycomb is nearly 30% more than the sum of mean crushing stresses of its corresponding components. At the end, an experimental study has been performed to examine the effects of filling the honeycomb cellular structures with polyurethane foam on the peak load to mean crushing load ratio of the these structures.