Quasi-static compressive behavior and energy absorption of novel cellular structures with varying cross-section dimension

Cellular structures exhibit attractive mechanical properties like lightweight, high specific stiffness, and excellent energy absorption. Materials and structures design offers valuable enhancement of nature honeycombs. This work proposed a variable cross-section unit cell to improve compressive and energy absorption properties of the cellular structure constituting these unit cells. In the developed variable cross-section unit cell, the inclined cell walls of the traditional accordion honeycomb were flipped at an angle in the out-of-plane direction or swept along a cousin wave path. The Fused Deposition Modeling (FDM) technique was employed to prepare honeycomb specimens from polylactic acid (PLA). In-plane quasi-static compressive tests were carried out to investigate mechanical behavior and energy absorption of the designed honeycomb structures. The results indicate that the design of the variable cross-section in the width direction enhanced compressive strength and improved energy absorption capability. Based on the variable stiffness characteristic of PLA, isothermal compression experiments were conducted to investigate the temperature dependence of the compressive behavior. This work provides a demonstration for improving the mechanical performance and energy absorption of lightweight cellular structures.