A gradient-like thin-walled tube via adhesive bonding for energy absorption

Abstract

Gradient wall thickness design is a typical method to enhance the energy absorption efficiency of thin-walled structures. Compared with conventional uniform-thickness thin-walled structures, gradient wall structures are mostly fabricated using electrical discharge wire cutting, which significantly increases their production cost and limits their practical engineering applications. This paper proposes a novel approach to fabricate gradient energy-absorbing structures using adhesive bonded metal plate, which enables rapid fabrication while maintaining energy absorption performance. Mechanical experiments were conducted on adhesive joints to calibrate the constitutive parameters of the adhesive layer and determine the thickness of the adhesive layer and surface treatment conditions. Numerical simulations of the out-of-plane compression and crushing behavior of four adhesive-bonded rectangular tube configurations were carried out to analyze their energy absorption characteristics and structural deformation. Based on the experimentally validated model, the effects of adhesive width ratio and wall thickness of metal plate on the energy absorption for these bonded structures were investigated. Finally, a comparative analysis of the energy absorption performance between adhesive-bonded energy-absorbing structures and traditional gradient-thickness structures was conducted to verify the feasibility and effectiveness of the adhesive-bonded structures. The results indicate that increasing the adhesive width and thickness of metal plate within a certain range can significantly improve energy absorption performance. However, further increases lead to significant degradation in specific energy absorption, along with an elevated risk of adhesive layer failure at the structural ends. In addition, compared to traditional gradient thin-walled structures, the bonded structure shows improvements of 22.50 %, 19.97 %, and 6.37 % in EA, MCF, and SEA, respectively, demonstrating excellent energy absorption performance and great potential for application.