On multi-stage deformation and gradual energy absorption of 3D printed multi-cell tubes with varying cross-section

Abstract

Thin-walled structures are widely used in passive safety systems due to their excellent lightweight and controllable progressive deformation performance. While designing to improve the energy absorption performance of thin-walled structures, it is also crucial to consider reducing the damage received by protected objects during accidental collisions. In this work, stepwise and continuous graded multi-cell tubes with varying cross-sections were proposed based on the fused deposition modeling technique to achieve a gradual energy absorption process. Compression responses and energy absorption characteristics of the graded multi-cell tubes were investigated by quasi-static compression tests. Experimental results showed that the stepwise graded multi-cell tubes produced obvious multi-stage deformation and energy absorption during axial compression. The specific energy absorption presented an upward trend with the increased number of stepwise segments. For the same ranges of cross-section variations, continuous graded multi-cell tubes exhibited more plastic hinges and better energy absorption performance due to the absence of discontinuous interfaces. In addition, continuous graded multi-cell tubes showed continuous folding deformation with the gradually decreasing folding wavelength. Thus, it exhibited a steadily increasing trend in crushing force and realized the gradual energy absorption mode.