Bioinspired staggered diaphragm design of multi-cell thin-walled structures for enhancing compressive performance

Abstract

Inspired by the stem of the bird-of-paradise plant, a group of novel multi-cell structures with staggered diaphragm arrangements were proposed to improve their energy absorption and load fluctuation. These structures were fabricated by the fused deposition modeling technique and made from chopped carbon-fiber-reinforced polyamide. The effects of the different staggered diaphragm arrangements (SDA1, SDA2 and SDA3) on the energy absorption characteristics and deformation behaviors of multi-cell structures were investigated by the axial compression tests. The results suggested that compared to the non-staggered diaphragm arrangement (NSDA), SDA3 showed a 30.085 % increase in the specific energy absorption (SEA) and a 45.674 % decrease in the undulation of load-carrying capacity (ULC). The mechanism analysis indicated that diaphragms limited the movement of thin walls at junctions between thin walls and diaphragms, promoting the formation of plastic hinges. The staggered diaphragm design created more junctions, contributing to additional plastic hinges for energy absorption. In addition, staggered diaphragms induced the peak response forces of thin wall separation, thereby decreasing load fluctuation. Based on mechanism analysis, the superposition method was carried out to analyze the fluctuation characteristics of response force curves. The comparisons between experimental and theoretical results presented that the method was an effective and accurate analysis way for 3D-printed multi-cell structures with diaphragms.