Quasi-static axial compression behavior of constraint hexagonal and square-packed empty and aluminum foam-filled aluminum multi-tubes

The axial crushing behavior of empty and Al close-cell foam-filled single Al tubes and Al multi-tube designs (hexagonal and square) were investigated through quasi-static compression testing. The effects of foam filling on the deformation mode and the crushing and average crushing loads of single tubes and multi-tube designs were determined. The foam filling was found to shift the deformation mode of empty single tube and empty multi-tube designs from diamond into concertina. In multi-tube designs the constraint effects and the frictional forces were found to increase the average crushing loads over those of single tubes. It was also found that foam filling induced a higher strengthening coefficient in multi-tube than single tubes. Although foam filling increased the energy absorption in single tubes and multi-tube designs, it was not effective in increasing the specific absorbed energy over that of the empty tubes. However, multi-tube designs were found to be energetically more effective than single tubes at similar foam-filler densities, proving a higher interaction effect in multi-tube designs.