Topology Optimization Of Wheel Based On Vibration Level Difference

With the development of urbanization, transit system with its many advantages has become indispensable component of urban transportation structure. However, since most of the urban rail transportation in densely populated areas, the noise problem of urban rail transit limits its potential development. In this paper, aiming at the urban rail transit wheel-rail noise problem, straight and S-type spokes wheel commonly used in urban rail transit vehicles are taken as the study objects, vibration and sound radiation characteristics of the two wheels are analyzed.In this paper, straight and S-type spokes wheel commonly used in urban rail transit vehicles were taken as the study objects, and vibration and sound radiation characteristics of the two wheels were analyzed. Considering the complexity of acoustic calculation in the traditional acoustic optimization and hardly-obtained optimization scheme, wheel topology optimization method based on vibration level difference was proposed. Using this method, two wheel spokes were optimized. Furthermore, the acoustic radiation and the strength were verified. The results show that new acoustic topology optimization scheme played a great effect on noise reduction. Topology Optimization of Wheel based on Vibration level difference is feasible.The main contents of this paper are as follows:(1) According to the standards of the Ministry of railways, straight and S-type spokes wheel taken as the study objects, finite element models were established.(2) Using modal analysis and frequency response analysis on the finite element model of straight and S-type wheel spokes, the modal frequency and vibration mode of the wheel were obtained, and acceleration admittance characteristics of the wheels are analyzed. Moreover, according to accelerations of reference points in the respective bands, the vibration level difference of the original straight and S-type spokes wheel are calculated.(3) Acoustic radiation characteristics were applied to analyze the straight and S-type spokes wheel. From the view of energy, acoustic radiation characteristics of the wheels are analyzed by using radiated sound power, providing the basis for noise verification of the wheel.(4) A layer of 4-mm material laid on the each side of the original straight and S-type spokes is regarded as the designed area of topology optimization. This paper introduces wheel structural vibration level difference as topology optimization objective function, and construct the topology optimization model of straight and S-type spokes wheel. Then the noise and intensity of the newly-attained acoustic topology optimization model are verified, The noise of the optimized straight spoke reduces by 11.99%, and the reduction of the S-shaped spoke is 11.5%. The results indicate that new acoustic topology optimization scheme plays a great effect on noise reduction.