Key Design Parameters of Medium Damping Trapezoidal Sleeper Track Structure
To study the dynamic characteristics of medium damping trapezoidal sleeper tracks,a vehicle trapezoidal sleeper track-tunnel vertical coupling dynamic model was established using the direct stiffness method.The influence of the vertical static stiffness of the damping pad and the thickness of the trapezoidal sleeper on the dynamic response of the steel rail,sleeper,and tunnel was analyzed.The results show that when the static stiffness of the damping pad is between 15~30 kN/mm,the damping effect meets the moderate damping requirements.The vertical static stiffness of the trapezoidal rail sleeper damping pad can be selected based on the specific vibration superscales of environmental sensitive points.Compared with ordinary integral track beds,when the vertical static stiffness of the damping pad in the trapezoidal sleeper plate is 25 kN/mm,the trapezoidal sleeper has better damping effect in the frequency range above 40 Hz.The increase of trapezoidal sleepers thickness can reduce the vertical displacement of steel rails and sleepers,and improve the damping performance by increasing the vibration mass.When the thickness of the trapezoidal sleeper increases from 0.15 m to 0.35 m,the vertical displacement of the steel rail,the vertical displacement of the sleeper,and the vertical acceleration of the tunnel decrease by 7.73%,6.82%,and 18.18%,respectively.When connecting the medium damping trapezoidal sleeper track with the ordinary integral track bed,it is necessary to set up three 5.8 m transition trapezoidal sleepers in the laying section of the trapezoidal sleeper.The static stiffness of the damping pad of the transition trapezoidal sleeper should be prioritized according to the three-level stiffness transition scheme.
trapezoidal sleeper trackdamping pad stiffnesssleeper thicknesstrack transition sectionchange rate of rail deflection