Quayside Wheel/Rail Box Girder System Noise Prediction And Control

Quayside is crane of port. Working out noise and vibration problem is an urgent task for develop quayside manufacturing industry and meet the environmental demands. Wheel/rail and box girder system is the main noise source of quayside. To investigate thoroughly its generation mechanism and then to develop a theoretical model to model the noise so as to provide some control strategies are essential for decreasing quayside’s noise and improving its quality. It is known that, during quayside operation, wheel and rail can generate wheel/rail excitation forces due to the interactions caused by the wheel/rail roughness. Funded by the Natural Science Foundation of China-Dynamic analysis of large complex built-up structures with parameter uncertainties (Contract No.51175300) and Shandong Science Foundation project-Near-high-frequency vibro-acoustic analysis of typical engineering rib-stiffened plates (Contract No. ZR2011EEM009), in the present research, the vibration and noise behaviors of wheel/rail system are mainly investigated with a clear aim to reduce and/or to control the wheel/rail noise. The wheel/rail dynamic coupling theory, vibration isolation methods, and structural acoustical radiation theory are combined to yield the wheel/rail noise prediction model. The effectiveness of the model is verified by comparing with the relevant results of existing references and also with the field test data. It thus allows some control strategies of wheel-rail and box girder system noise to be proposed.The main research results and some important conclusions of the paper are summarized as follows:(1) Through a comprehensive analysis of domestic and international sound power measurement standards, the sound power measurement scheme that is suitable for quayside is researched. By analyzing the sound characteristics of each stage of quayside operation and using the microphone array technology, quayside’s main noise source and vocal band is identified.(2) According to the structural characteristic of quayside wheel/rail box girder system, a theoretical prediction model of wheel/rail box girder system noise is established. First of all, the wheel/rail excitation force calculation model caused by wheel/rail roughness and the contact filter effect is set up; secondly, the dynamic analysis model of rail-pad-box girder vibration isolation system is established for calculating the forces of wheel rail and box girder; and finally, Virtual.Lab (BEM) are used to calculate the wheel noise radiation sound power, while VA-1(SEA) is used to calculate the rail and box girder noise radiation sound power.(3) A wheel/rail box girder system noise prediction model is set up for a typical quayside structure. The rail roughness, wheel, rail, rail pad and box girder mobility are obtained by measurements. Then the wheel/rail excitation force is calculated and validated by comparing with typical train’s wheel/rail excitation force. Wheel rail and box girder forces are calculated and treated as the input excitation to calculate the radiation sound powers of wheel rail and of the box girder, respectively, in the frequency band of50-2000Hz. The effectiveness of the model is verified by comparing with field test data. The research finds that the wheels’sound radiation can be neglected.(4) Based on the prediction model of wheel/rail box girder system noise, the influences of load, rail roughness, rail pad stiffness, damping for rail and box girder sound radiation are investigated. It is found that the larger the load, the smaller the wheel/rail box girder noise is, but the influence of load is found fairly small with the influence level to radiation sound power level of the wheel/rail box girder only about2-3dB; if the wheel/rail roughness is reduced by half, the caused wheel/rail excitation force is reduced by half, i.e., the radiation sound power level of the wheel/rail box girder is reduced by6dB; reducing the pad’s stiffness by half has little influence on the sound radiation of rail, but can reduce significantly the box girder’s radiation sound power level by7dB; pasting damping sheet can effectively reduce the radiation sound power level of rail and box girder by6-7dB.