Investigation of dynamic responses of a sled sample with mass and variable applied forces to perturbation on the rail surface

In the present paper, the dynamic responses of a variable mass sled sample under the variable forces of propulsion, lift, drag and friction are investigated. First, by presenting a complete model of the various components of the sled system, the governing equations are extracted and the state space method is used. Then the variable forces applied to the designed sled model are extracted. In order to validate the results of the analytical method, the natural frequencies of the sled laboratory model are obtained experimentally. The first and second natural frequencies of the sled were 12.8 and 21.4 Hz, respectively, which were in good agreement with the analytical results. The results show that due to the disturbance applied to the sled, the dampers damped 40% of the vibrations. Also, in all cases, the oscillation rate of the rear sleeper is more than the front sleeper, this is due to the effect of the turbulence of the front sleeper on the rear sleeper. On the other hand, variable forces increase the sled displacement by 10%.