Abstract: Aiming at the slack problem of the sliding bolt connection of the third rail current receiver, by establishing a contact finite element model of the current rail and the third rail, the track irregularity spectrum was used as a vibration source to simulate the optimal running speed interval of the train from the contact force level. And the vibration load was extracted. The correctness of the model was verified by using the Yamamoto method by establishing a bolt connection model. The relationship and the change rule between the residual preload force and the train running speed, the initial pretension force, and the friction coefficient were analyzed according to the actual operating conditions. The results show that the residual preload decreases the most during the initial stage of operation，too small or too large initial preload will affect the reliability of the connection. When the train runs in the optimal speed range, choosing the appropriate initial preload and fcoefficient of friction can improve the anti-loose performance. The analysis results have certain reference significance for studying the loosening mechanism and anti-loosening of the slide bolt connection of the third rail current receiver.
Key words: third rail train receiver slide; bolt connection; residual preload; initial preload; running speed; coefficient of friction