Experiment and numerical simulation study on the bionic tubes with gradient thickness under oblique loading

A class of bionic gradient thickness (BGT) tubes with 2 cross-sectional shapes (circle and rectangle) are proposed. The energy absorption and deformation modes of four thin-walled tubes, including a bionic circular tube (BCT), and a bionic rectangle tube (BRT) with gradient thickness, and the counterpart uniform-thickness (UT) tubes, namely circular tube (CT) and rectangle tube (RT), are analyzed by Ls-Dyna. Before detailed analysis, the simulation and bionic design are verified by quasi-static experiments, which show that the BCT has better deformation than the CT, and the experimental curves also are well consistent with the simulation. The BCT has a better energy absorption capacity when subjected to different oblique loading angles. The selection and parameterization of sample points are studied based on full-factor tests. The design factors significantly affect the specific energy absorption (SEA) and peak force (PF) of the BCT under multi-angle oblique loading. Finally, the multi-objective optimization design considering the load angle is conducted to obtain the optimal design of the BCT. The optimum BCT has a 9.3% higher SEA compared with CT. Moreover, there is a mass reduction of 4% than the CT.

Automated summary

This study proposed a bionic tube design with different cross-sectional shapes and gradient thickness, and investigated their energy absorption and deformation performance through simulation and experiments. Design factors affecting the performance of bionic tubes were determined by full-factor tests, and a multi-objective optimization design was conducted to obtain the optimal design.