High energy absorption efficiency of thin-walled conical corrugation tubes mimicking coconut tree configuration

In this study, a new tubular corrugated configuration mimicking the coconut tree profile, here named conical corrugation tube (CCT), was proposed, in an attempt to enhance the energy absorption, minimize the initial peak crushing force, and stabilize the crushing process. The effects of geometrical features, especially tapered angle and wavelength of CCTs on the deformation mode and energy absorption characteristics, were investigated through a series of numerical simulations. The results showed that the deformation modes of CCTs could be mainly classified into four modes, which were clearly influenced by the tapered angle and the wavelength of the CCTs. Moreover, the initial peak force of the CCTs was reduced significantly compared with that of the circular straight tube and the tapered tube. In addition, the undulation of the load-carrying capacity parameter, which is used to evaluate the stability of the crushing force, is minimized, and the CCTs produced smoother force-displacement curves compared with the circular straight tube and the tapered tube. Finally, a theoretical model was proposed to predict the mean crushing force of CCTs under dynamic impact loading. The theoretical results showed a good agreement with the numerical results.