OS1722 ハニカム構造の軸圧潰に見られる材料のひずみ速度依存性

Abstract

The axial crushing behavior of metal honeycombs was studied primarily by the experiments with laying emphasis on the effects of strain rate on those characteristics as energy absorbers. To evaluate the strain rate dependence of materials, A3003 aluminum alloy, SUS430 stainless steel and C1100 tough-pitch copper were used to fabricate honeycomb structures in laboratory. Then, the axial crushing tests under low-speed and free-fall impacting conditions were carried out. SUS430 and C1100 show certain strain rate dependence so that fabricated honeycomb structures also show strain rate sensitivity to some extent. However, the deformation of axial crushing honeycomb is not uniform but is localized at each stage of the progressive plastic buckling. The results show the effect of strain rate on an indicator of energy absorption ability such as mean buckling stress is less than that on the flow stress of foil material itself. The numerical simulations, which took the influences of the plastic deformation of adhesive layer and the fracture of adhesively-bonded joint into consideration, were also conducted by the FEM code LS-DYNA to confirm and understand the behavior.