Analysis Of Steel Switch Sleeper's Vibration Performance And Study Of Parameter

Steel switch sleeper is a special kind of switch sleeper, which is mainly used at the switch traction points. And the switching equipments can be set in it, for the convenient operation of large maintenance machine. But because of its special structure types and stress modes, it cannot match the adjacent concrete switch sleepers in stiffness, which would form longitudinal rail stiffness irregularity. To reduce the rail dynamic irregularity for moving train, it is necessary to analysis vibration performance of the steel switch sleeper.Firstly, this paper established a mechanical model of steel switch sleeper and common concrete switch sleeper separately. In the models, fasteners are simplified as spring dampers, the sleeper is regarded as a rigid mass, the contacts between ballast bed and sleeper is also simplified as spring dampers, the rail vertical displacement set as the system drive. For the steel switch sleeper, there are two groups of fasteners on it, two-point eccentric supports under it, and it has two degrees of freedoms which are ups and downs as well as rolling; And for the concrete switch sleeper, there is one fastener groups on it, one-point eccentric supports under it, and it has only one degree of freedom which is ups and downs.According to the mechanical models, established oscillatory differential equations for the steel and concrete switch sleeper separately, and then deduced transfer functions of the two systems. Using the system transfer functions, make the compared analysis of the two in vibration performance.By the system responses which got from transfer functions, studying the parameters of steel switch sleeper. In the frequency-domain, analysis the influences of the quality, stiffness of the fasteners and cushion layers, stiffness of ballast-subgrade on steel switch sleeper's vibration performance. Summary from research: increasing the quality, reducing the stiffness of the fastener and cushion layers, increasing the stiffness of ballast-subgrade can narrow the gap between the steel switch sleeper and concrete switch sleeper, and decrease the dynamic longitudinal railway stiffness irregularities.