硬質高分子ラティス構造の複数回圧縮下におけるエネルギ吸収特性

抄録

Lattice structures are emerging due to the increasing demand for materials that are lightweight and can ensure safety, which is critical for sustainable development. This study aims to gain some knowledge on the characteristics of lattice structures with excellent energy absorption properties, and to contribute to the development of reusable energy-absorbing materials. Lattice structures with three types of unit cell topologies-body-centered cubic (BCC), Cruciform, and face-centered cubic (FCC)-were fabricated with acrylic polymer and subjected to multiple compression tests to investigate the strain recovery characteristics and changes in compressive and energy-absorbing properties. All structures exhibited significant strain recovery to 69-81% of their uncompressed height after sufficient time following compression. However, Young's modulus, plateau stress, and densification onset strain decreased after each cycle. Consequently, the specific energy absorption decreased significantly, especially after the first compression. The structure exhibiting strut buckling during plastic collapse (Cruciform and FCC) absorbed a large amount of energy during the first compression but showed a significant decrease during the second and subsequent compressions. On the other hand, the rate of decrease in specific energy absorption for the structure without strut buckling (BCC) was relatively small, suggesting that preventing strut buckling can suppress the decrease in specific energy absorption.