According to the basic relations of wheel/rail interaction with spectrum analysis method and considering the area of contact between the wheel and rail,the wheel/rail coupled vibrations excited by the small-scale roughness of the running surfaces of the wheel and rail are studied.The formulas of the space-averaged spectra of vertical and lateral vibration level of the wheel and rail are presented.Not only the vertical impedance and lateral impedance of steel rails,but also the radial impedance and axial impedance of wheels are successfully deduced.In the analysis of the steel rails′ vertical impedance,considering the sleepers′ quality and using the model of double-layer continuous resilience foundation beams,the rails are divided into Euler Beams and Timoshenko Beams.In the analysis of the steel rails′ lateral impedance,the rails are regarded as double structure.The rail heads are considered as Timoshenko girders considering shearing force and rotation and the webs are considered as spring and damp associating heads and foots.In the analysis of the wheel impedance,the wheel is simplified as an elastic circle loop,which taking the rigidity of web plate into consideration.The tread is regarded as an elastic loop,and the web plate is regarded as a spring component connecting wheel tread and wheel axle.Based on the wheel/rail coupled vibration research,considering the effects of the ground reflection the prediction expressions for the sound pressure level spectrum of the wheel/rail rolling-noise are given by means of the application of the structural sound radiation theory.In order to demonstrate the accuracy of this expression,the calculation results of wheel/rail high-frequency response and wheel/rail noise are compared with the test results in authorized reference.And the wheel/rail rolling-noise from existed railways in our country are predicted and measured.The numerical results and the measured ones agree well.With this existing model of wheel/rail rolling noise,the wheel/rail noise frequency,distance and
