Analysis On Acoustic Radiation Of High-Speed Flexible Linkage And Structural Optimization Based On Noise Attenuation

Various high-speed flexible mechanisms are used popularly in modern industries. Due to their small damp, and the coupling of their large overall displacement and local distortion, they are ready to vibrate under exterior disturbance, which usually leads to intense acoustic radiation, then deteriorate the circumference. These days more and more attention has been paid on Noise pollution, and noise control has become one of the most important tasks in the design of modern mechanisms. It is a challenge project for us to predict the acoustic radiation of high-speed mechanism, and try to depress it effectively. Which is also one of the key problems to solve in the design of mechanical products, aeronautics and astronautics products, and martial products. In this study, the analysis of acoustic radiation of flexible linkage mechanism, noise attenuation, and other problems involved in the study of mechanism acoustic radiation are carried out, and some conclusions are obtained.In this dissertation, based on the elasto-dynamic analysis of flexible linkage mechanism, the dynamics equations of the mechanism are obtained. In precondition with the solving of dynamic response of the mechanism, the calculation of acoustic radiation performance index is studied, and the rules of acoustic radiation of flexible linkage mechanism are discussed via several simulation examples. With the wave number analysis of the structural vibration of flexible mechanism, the relationship between structural vibration and structural acoustic radiation are studied. Based on the conclusion of wave number analysis, a new dynamic equation taking the measure of structural acoustic performance is obtained by a set of transformation, which is much convenient for us to discuss the noise attenuation.The structural optimization based on noise attenuation is studied, in which the thickness of each link is taken as the design variable, and the weighting sum of structural mass and measure of the structural acoustic performance is taken as the synthesis performance index. Modified constrained variable metric method is adopted in this optimization, and the application of perturbation method in the re-analysis of the structure is studied.