Numerical simulation analysis of sleeper damage under dynamic load based on discrete element method.

• The influence of load factors on the damage of sleeper is analyzed by discrete element method. • The parallel bond degradation model is introduced to realize damage. • The influence of the range of sleeper suspension and the stiffness of the bottom support on the damage is analyzed. To analyze the damage development of concrete sleepers during railway operation, the discrete element method and the parallel bond degradation model are introduced into the damage analysis of concrete sleepers for the first time. The cracking resistance and dynamic characteristics of the sleeper model are verified by comparing the existing literature. The influence of load and the stiffness of the bottom support on the damage development of the sleeper is considered and the following conclusions are drawn: with the increase in the load amplitude, the damage of the sleeper will increase nonlinearly; under the conditions of the same time and the same load amplitude, the number of cracks of the sleeper will increase with the increase of load frequency, and increase exponentially with the number of loads. Different support stiffness at the bottom of the sleeper will change the dynamic characteristics of the sleeper under load, thus changing the damage development of the sleeper. For the sleeper with full support at the bottom, when the support stiffness at the bottom is low, the center of the sleeper is more likely to be damaged. When the support stiffness at the bottom of the sleeper is large, hanging the center of the sleeper about 1/3 of the length of the sleeper can reduce the damage to the center of the sleeper. The research results show that this method can be applied to the study of sleeper damage and provide a new idea for the structural damage of sleepers. [ABSTRACT FROM AUTHOR]