Static and dynamic axial crushing of self-locking multi-cell tubes

A new type of self-locking multi-cell structure fabricated by assembling four C-shaped open sections is proposed in this paper. Quasi-static and dynamic experimental tests are performed to investigate the axial crush resistance and energy absorption characteristics of this type of structures. The experiment results show that the SEA of the assembled multi-cell sections is 35-40% and 40-50% higher than that of the constituent C-shaped elements for quasi-static and dynamic loading, respectively. Numerical analyses are carried out to simulate the experiment and perform the parametric study on the influences of geometric parameters, boundary condition and load speed on the crush resistance of structures. The behavior and performance of single C-shaped open sections are also studied, and the interaction effects originated from the self-locking features are investigated quantitatively. In addition, theoretical expressions are derived to predict the crush resistance of the assembled self-locking multi-cell sections. Comparisons show that the theoretical expressions can predict the static and dynamic mean crushing forces of the self-locking multi-cell structures with errors below 5% in most cases.