Numerical Analysis and Theoretical Prediction of Axial Crushing Characteristics of Mixed Thin-walled Tubes with Dual-variable Attribute.

Thin-walled structures with varying thickness (single variable attribute) had been proven to be able improve energy absorption characteristics. In order to further study the energy absorption characteristics of thin-walled structures whose material properties changed as the thickness changing, a novel type of mixed thin-walled tube with axially-varying thickness and material were proposed in this paper. The finite element (FE) model was validated under axial quasi-static loading firstly, and seven groups simulation models of thin-walled tubular structure were established. The simulation results showed that the dual-variable attribute tubes can ensure high energy absorption and reduce the initial peak crushing force effectively in the crushing process. Furthermore, the maximum crushing force efficiency of steel-aluminum mixed tube can reach 2.77, while the aluminum mixed tube increased the crushing force efficiency to 1.24. Subsequently, a analytical model for dual-variable attribute tube was established and the theoretical mean crushing force calculation formula can be derived. The simulation and theoretical results were wirelessly close, except that the error of SUT5 was about 11 %. Therefore, the theoretical prediction results were in good agreement with the simulation results, and the theoretical prediction method can provide some reference for the design of double variable tube. [ABSTRACT FROM AUTHOR]