Research On Vibration And Sound Acoustic Characteristics Of Honeycomb Sandwich Panel With Elastically Restrained Boundary Conditions

Honeycomb sandwich panel structure is widely used in the aerospace field.The research on its vibration and noise characteristics has long been concerned,but the existing research is mainly limited to several simple boundary constraints,such as simple support and clamped support.On the other hand,the constraint boundary condition is one of the important factors affecting the vibration,sound radiation and sound transmission characteristics of honeycomb sandwich panels,Play a key role in structural vibration and noise control,play a key role in structural vibration and noise control,Therefore,it is of great theoretical and engineering significance to systematically analyze the influence mechanism and law of the constraint boundary by studying the vibration and acoustic characteristics of the honeycomb sandwich structure under the elastic confinement boundary.In this paper,a series of theoretical modeling and numerical simulation work are carried out around the vibration and acoustic characteristics of honeycomb sandwich panel structures under elastic confinement boundary conditions.The details are as follows:(1)First,in order to obtain a theoretical model of the vibration and acoustic characteristics of the honeycomb sandwich structure,the honeycomb core layer is processed based on the homogenization equivalent idea.By comparing the equivalent theories of three honeycomb sandwich panels,including sandwich sandwich panel theory,honeycomb panel theory and equivalent plate theory,the deformation characteristics of honeycomb sandwich layers and the errors of various theories and finite element analysis are systematically analyzed.Established the foundation for vibration and acoustic analysis of honeycomb sandwich structures(2)The free vibration theoretical model of honeycomb sandwich plates with elastic constraint boundary condition is established by using the 2-D modified Fourier series method,in which the in-plane?transverse?rotation vibration displacements along five directions are all expressed as the superposition of a double Fourier series and four supplementary functions in the form of ten product of a polynomial function and a single series expansion.The use of these supplementary function can overcome the discontinuity problems encountered in the displacement partial differentials at the boundary.By comparing the calculated results with calculated from FEA approaches validates that the theoretical method has accuracy in solving the vibration characteristics of honeycomb sandwich structural with elastic constraint boundary condition.(3)Based on the vibrational theoretical model of the elastically constrained boundary honeycomb panel structure,a theoretical model of acoustic radiation structure of honeycomb sandwich panel structure under elastic confinement boundary conditions is proposed by using the two-dimensional improved Fourier series method.The lateral displacement response and velocity response of the honeycomb sandwich panel are obtained by solving the solution.By comparing the calculated results with calculated from FEA approaches validates that the theoretical method has feasibility in solving the vibration characteristics of honeycomb sandwich structural with elastic constraint boundary condition.The vibration response of the honeycomb sandwich panel is used to indicate the radiated sound pressure of the honeycomb sandwich panel by Rayleigh integral method.The influence of boundary constraint stiffness on the radiated sound power and radiation efficiency of honeycomb sandwich panel is discussed,which provides a basis for acoustic vibration optimization of honeycomb sandwich panel structure.(4)Based on Virtual.Lab Acoustics Simulation Software,The influence of material parameters and boundary conditions on the acoustic loss of honeycomb sandwich panel structure is calculated and analyzed,which provides a basis for the sound insulation performance design of composite sandwich panel structure.