Crashworthiness study of double-layer sinusoidal tubes under axial loading.

Thin-walled tubes are widely used as energy absorption devices because of their excellent crashworthiness. In this paper, a novel tubular configuration with a double-layer sinusoidal corrugated section, namely, a double-layer sinusoidal tube (D-LSCT), is proposed to improve the energy absorption capacities. Quasi-static compression experiments and finite element simulations were used to analyse the axial crushing behaviour and energy absorption performance of the D-LSCTs. The results revealed that the geometric parameters had a significant effect on the crashworthiness of the D-LSCTs and that the D-LSCTs had four deformation modes: ordered progression extensional mode (OPEM), ordered progression inextensional mode (OPIM), inextensional mode (IM) and mushroom mode (MM). OPEM and OPIM were more ideal modes, while the IM and MM were unideal modes. To further improve the deformation stability, D-LSCTs were transformed into a three-layer structure by superimposing a regular polygon tube. Experiments and simulations showed that the improved structural design can indeed stabilise deformation and improve the crashworthiness performance. [ABSTRACT FROM AUTHOR]