The Research Of The Mechanical Structure Vibration Noise Based On The Sound Of Fluid-solid Coupling

Rotating machinery is an important part of mechanical equipments. With the development of science and technology progress and industrial automation, rotating machinery fault diagnosis is more and more valued.The use of traditional vibration signal for fault analysis and diagnosis has been very mature, but for some large equipment modernization, it is analyzed by using vibration signals is difficult, therefore, by using acoustic signal was put forward and study of the fault diagnosis of mechanical equipments.In this paper, Researching the mechanical structure vibration noise based on the sound of fluid-solid coupling, the ACTRAN vibration acoustic simulation software was used to explore the relationship between structural vibration and sound simple simulation, combining with the results of simulation experiments and research, thus formed on the relationship between the mechanical structure vibration and sound theoretical basis, to solve the problem of the engineering practice has certain guiding significance, and the research of fault diagnosis by using acoustic technology positively influence.In this paper, author describes the basis of vibration and acoustic, and carefully analysises of all kinds of piezoelectric material, PZT piezoelectric ceramic materials are selected as the material of experiments piezoelectric ceramic piece.By using acoustic simulation software ACTRAN to simple sphere and cube model of normal structure and fault structure to analyze the simulation excitation, at the same time in half a quieter room using microphone array, and analyzes the experiment of the signal generator equipment, use of piezoelectric ceramic piece to different frequencies of vibration of structure, collects the structure under different excitation frequency of the vibration signals and the acoustic pressure signal by using labview, at the same time, the collected data has been analysised by using MATLAB, through the analysis of the experimental results agree with the simulation results, i.e., when the vibration frequency is less than 240 Hz, with the increase of vibration frequency, the structure of sound pressure is reduced, and the vibration displacement amplitude and vibration displacement amplitude was positively correlated with the change of sound pressure.When the excitation frequency is greater than 240 Hz, with the increase of vibration frequency, the structure of sound pressure and vibration displacement amplitude increase constantly, and 1220 Hz for cube structure natural frequency or for natural frequency of the frequency doubling.In the fluid, sound field sound pressure is around the structure to the external radiation.For structures with crack (failure) is analyzed by fault location of sound pressure and vibration amplitude changes more apparent, and the corresponding fluid acoustic field distribution of crack of sound pressure change is larger.