Study On The Vibration Characteristics Of A New Type Of Active And Passive Viscoelastic Damping Laminate

Thin plate structure is a commonly used structure in the industrial field.It has the advantages of light weight and good heat dissipation performance.However,due to its low rigidity and low damping,the vibration and sound radiation is usually large.It is one of the effective methods to reduce the vibration and noise of the plate structure to study the surface damping treatment technology of the thin plate structure and develop a new and efficient viscoelastic damping layer structure to effectively improve its damping characteristics.In this paper,based on the tensile bending deformation and shear deformation energy dissipation characteristics of the viscoelastic layer in the damping composite plate structure,a new passive composite damping layer with elastic constraints(ECCDL)structure with elastic constraints is proposed.The 0-3 type active viscoelastic composite layer(VEC)structure embedded in the periodic array piezoelectric film,and the damping energy dissipation mechanism and characteristic analysis were carried out.The specific research work and results are as follows:The dynamic model of ECCDL plate is established based on thin plate theory,assumed modal method and Lagrange equation.By using COMSOL software,the correctness of the model is verified by an example.The free vibration and forced vibration of the ECCDL plate with local lay and simple support are analyzed.By studying the displacement frequency response results at different excitation points and different response points,two vibration modal testing methods are summarized.The influence of thickness of viscoelastic layer,material loss factor and laying shape on the vibration of ECCDL layer was studied.The new passive ECCDL layer is a generalized free damping layer structure with high modal loss factor.Based on the piezoelectric theory and Hamilton principle,the dynamic model of 0-3 VEC plate was established.By using COMSOL software,the in-plane distribution of tensile strain and shear strain of the 0-3 TYPE VEC layer under constraints was revealed through the static bending analysis of the composite plate.The energy dissipation mechanism of the 0-3 type VEC layer was further revealed through the analysis of damping characteristics and the comparative study of vibration of different structures.The influence of area,thickness,quantity,thickness of middle and lower layer and different filling materials on the vibration of the composite plate was studied.The new type of active 0-3 VEC layer can optimize the distribution of damping and stiffness,and has better damping effect.For the 0-3 piezoelectric active viscoelastic composite structure,COMSOL multi-physical field coupling simulation,the feedback control of the 0-3 VEC plate was studied based on the feedback control of induced layer voltage and transverse velocity.The displacement frequency response controlled by the polarity was obtained by laying several type the 0-3 VEC layer patches on the vibration substrate.The VEC plate under active control has better vibration damping effect.This paper aims to develop a new type of highly efficient viscoelastic damping layer structure,discuss its damping energy dissipation mechanism and vibration characteristics under parameter changes,and provide a theoretical basis for damping design and vibration and noise reduction of thin plate structures.