Study on energy absorption characteristics of squeezing energy-absorption structure composed of cylindrical pin and groove

Anti-climber is a crucial component in the passive safety system of trains. It absorbs collision energy, reduces the damage to carriage, and protects safety of occupants during the train collisions. Energy-absorption structure is a key part of the anti-climber, which should not only provide sufficient buffering force but also possess good stability of buffering force and excellent resistance to eccentric loads. This paper explored the energy absorption characteristics of a squeezing energy-absorption structure composed of cylindrical pin and groove. A set of such energy-absorption structures composed of cylindrical pins with the same diameter and grooves with different groove widths were designed. Based on a universal material testing machine, quasi-static energy absorption characteristic tests were carried out to obtain buffering force history curves of the energy absorption structures. Experimental results show that the buffering force of the energy-absorbing structure changes very smoothly and reaches a stable state after a short squeezing distance. As the groove width decreases, the amount of squeezing volume increases, and the steady buffering force increases. However, when the groove width is too small, it would cause the fracture of side walls of the groove at their roots and result in a decrease in steady buffering force. Meanwhile, a finite element simulation model of the energy absorption characteristics of the squeezing energy-absorption structure was established to simulate its energy absorption process. The simulation results agree well with the experimental results. They can well reproduce the changing pattern of buffering force and the influence of groove width on buffering force. By using the validated simulation model, factors such as side-wall thickness of groove and eccentric distance of cylindrical pin were studied for their effects on the energy absorption characteristics of the energy-absorption structure. The results indicate that as the side-wall thickness increases, the steady buffering force increases, but its increment gradually decreases. Also, the results reveal that as the eccentric distance of cylindrical pin increases, the steady buffering force gradually decreases, and the buffering force curve shows more violent fluctuation. © 2024, Central South University Press. All rights reserved.