Study On Wheel-Rail Noise Characteristics Considering Resilient Wheel Rubber Layer Block

With the rapid development of China’s economy,a number of large and medium-sized cities have opened rail transit operating lines.With the convenience of transportation comes serious noise pollution,subway vehicles through certain sections will produce ear-splitting noise,which not only reduces the comfort of passengers riding,but also causes serious impact on the residential and commercial areas along the line,and in serious cases will shorten the service life of wheels and rails,so it is important to carry out vibration and noise reduction of subway lines.Using resilient wheels has a significant effect on reducing vibration of the wheel track and reducing the noise of the wheel rail.The rubber of the current resilient wheel is divided into blocks that are evenly distributed between the wheel core and rim,which can effectively reduce the resilient wheel stiffness and improve the performance of the resilient wheel.Although the blocked rubber resilient wheel can effectively reduce the interaction force between the wheel-rail system,its form also destroys the wheel integrity and axial symmetry,which may have an impact on the wheel-rail vibration noise of the resilient wheel system and may also affect the operational matching of the line.Therefore,this thesis explores the effects of rubber parts and through impact on the wheel-rail noise characteristics of resilient wheels based on the finite element-boundary element method.The main research of this thesis is shown as follows:First,a wheel-rail noise prediction model based on a steady-state model of resilient wheels and an infinitely long steel rail is established.The excitation is applied at the center of the gap between the rubber blocks and at the nominal rolling circle directly above the center of the rubber blocks to simulate the forces in the rolling of the wheel on the rail to determine the effect of the number of rubber parts on the wheel integrity and axisymmetry.The wheelrail force and wheel-rail noise of the resilient wheel were then obtained using the moving roughness method.The results show that the effect of rubber content on wheel noise is large,however the effect on rail noise is small.The modulus of rubber and loss factor have a greater effect on wheel-rail noise,while Poisson’s ratio has a smaller effect on wheel-rail noise of resilient wheels.Second,considering the nonlinearity and large deformation of materials,a threedimensional transient rolling contact finite element model of the resilient wheel with different rubber parts is established.The conventional model does not take into account the wheel rotation effect,which introduces a large initial excitation in the initial stage and causes dramatic fluctuations in the wheel-track force.Therefore,in this thesis,the wheel rotation effect is considered in the implicit calculation,and the results show that the optimized algorithm will greatly reduce the wheel-rail force fluctuation caused by the initial shock,making the model enter the stable state faster,so that the length of the transition zone can be shortened,the dimension of the solution matrix can be reduced,the solution time can be shortened,and the computational efficiency can be improved.Finally,based on the three-dimensional transient rolling contact model introduced two types of impact conditions of rail welded joints and rail wave grinding,the changes of wheelrail force characteristics and wheel-rail noise when the resilient wheel passes unevenness are explored.The resilient wheel can exert the effect of vibration and noise reduction on the short wavelength welded joint line,while it performs poorly on the long wavelength line,which will make the wheel-rail noise higher than the steel wheel-rail noise.The resilient wheel has a certain vibration and noise reduction effect on all the wave mill lines selected in the thesis.