Research On The Power Transmission Of High-frequency Vibration Between Coupled Structures

The influence of high-frequency vibration in engineering is increasing.It will not only accelerate the structural exhaust but also damage the health of the relevant staff.Therefore,people pay more and more attention to the high-frequency vibration coupling structures.The statistical energy analysis(SEA)is widely used in the design of aerospace and vehicles to predict the high-frequency vibration response of the structure at work.The coupling loss factor(CLF),as the key parameter to improve the calculation accuracy,has always been the focus of the attention in acoustic-vibration coupling analysis.Most of complex structures in engineering are composed of basic elements such as beams and plates.This dissertation conducts a series of studies on the coupled loss factor between the coupled structures.Firstly,based on the wave theory,the variation of the transmission characteristics of the coupled beam structure with the connection angle and the section size is analyzed.Then the coupling loss factor is calculated between the beam structures considering the influence of axial force and temperature.Finally,the power flow between composite laminates and isotropic beam in a coupled structures is studied.The details are as follows:1.Calculating the transmission characteristics between coupled beams by the point impedance method.Considering the influence of the mode conversion and deformation coupling at the same time,the transmission characteristics between the coupled beam structures are calculated by the point impedance method.Taking the classical 'T' beam structure as an example,the transmission coefficient and CLF between beams are calculated and compared with the literature results to verify the correctness of the program.Then the influence of coupling angle,beam height and excitation frequency on the CLF between the two-beam is analyzed.2.Influence of axial force and temperature on the coupling loss factor between coupled beams.Firstly,the influence of axial force on the vibration of beam is considered,and the expression of the bending wave number of beam structure under axial load is derived.Then the variation trend of the CLF with the axial force and the cross-sectional shape of a double beam model is analyzed.Finally,the effect of temperature variation on the energy transfer characteristics between beams in a line-shape structure is studied.3.Prediction of power flow between composite laminates and isotropic beams.For the coupling system with composite laminates and isotropic beams,the relationships between wavenumber and azimuth and frequency of laminated plates based on the motion control equation of the structure.Through the bending wave transmission analysis,the coupling loss factor between the beam-laminated composite was calculated and compared with the VA ONE software results.This research provides guidance for design in engineering.