Analysis And Optimization Of Vibration And Acoustic Radiation Characteristics Of Rectangular Plate Structure

The problem of vibration acoustic radiation of structures is often considered in engineering.The problem of vibration acoustic radiation of structures has been widely regarded as a long-term research subject by researchers.Vibration and noise have great influence on the safety,durability and comfort of the structure.Thin plate is widely used in automobile body,ship,high-speed railway and airplane because of its light weight and good plasticity.However,the thin plate is easy to become the source of vibration acoustic radiation due to the lack of structural stiffness,which will adversely affect the safety of the structure and the recognition of the product.It is of great significance to predict the vibration acoustic radiation of thin plates rapidly and accurately if the variation of the vibration acoustic radiation characteristics of thin plates with structural parameters can be known at an early stage.This paper mainly completes the following work:(1)Based on the relevant theories of finite element method and combined with the theory of modal analysis,the finite element software Abaqus was used to establish the finite element model and conduct correlation analysis.Taking rectangular thin plate as an example,the effects of different constraints on the natural frequency and mode of vibration of the plate are studied.The influence of the position,quantity,aspect ratio and layout of the stiffened plate on the vibration characteristics of the stiffened plate was studied.(2)On the basis of studying and analyzing the vibration characteristics of thin plate,the acoustic radiation characteristics of thin plate structure are studied by combining finite element method and boundary element method.The effects of boundary conditions,material properties,number of bars,stiffening form,position and direction of stiffening on acoustic radiation characteristics of thin plate structure are studied.Moreover,Based on Isight optimization platform,the sequential quadratic programming method was applied to strengthen the stiffened plate structure while reduced its acoustic radiation power,achieving the effect of vibration noise control.(3)Finally,several examples of vibration and sound simulation models of carbon fiber composite boards were established.The acoustic radiation characteristics of carbon fiber composite boards were obtained through Abaqus and Virtural.Lab joint simulation.On this basis,some key parameters of carbon fiber composite boards were discussed for carbon fiber composites.The influence mechanism of the overall vibration and acoustic characteristics of the board,including the pavement angle,the number of plies,and the number of reinforcements.Taking the dimension parameters of the carbon fiber composite stiffened plate as variable,ISIGHT software was used to optimize the parameters.The results showed that the acoustic radiation power at the first frequency of the carbon fiber composite stiffened plate decreased by about 4dB after optimization.