Vibration Analysis And Parameter Study Of Locally Coated Constrained Damping Beam Under Elastic Boundary

Viscoelastic materials have been applied to vibration reduction and noise reduction technology for decades.Constrained damping structure can provide high structural loss factor,wide temperature and frequency range,with good vibration reduction effect.However,it is not difficult to find from the existing literature research that there are two problems to be solved.On the one hand,the current research on the constraint damping structure often focuses on the overall laying situation.However,the practical application often considers the weight and cost factors,so the local laying is more appropriate than the overall laying;On the other hand,most studies remain at the classical boundaries.However,the boundary conditions of the beam structure are often complicated,which will also lead to some differences between the prediction of its performance and the actual performance.It is also particularly important to take complex boundaries into account.A simple,convenient and efficient analytical model to evaluate the vibration characteristics of the locally coated constraint damping beam under the elastic boundary is presented based on the first-order shear deformation theory.By introducing the boundary spring technology to simulate the general elastic boundary,the viscoelastic layer uses the complex modulus model and chooses the orthogonal polynomial as the tolerance function.Uising the Rayleigh-Ritz method to derive the motion control equations of the locally coated constrained damping beam vibration the method obtains the inherent frequency and loss factor by solving the complex eigenvalue.For the theoretical model established in this paper,firstly,the convergence of the model is verified by changing the truncation order of the admissible function;then the calculation results in this paper,the calculation results in the reference example and the finite element calculation results are compared to verify the correctness and reliability of the calculation method in this paper.Given the large number of parameters involved in viscoelastic damping systems,the influence of the parameters is studied.Through the analysis of the displacement amplitude frequency curve and the loss factor,the influence of the parameters of the the damping beam is investigated.With the increasing coating rate,the damping performance of the local coating passive restraint damping beam will be enhanced and then weakened,so it also proves that the local coating treatment has more practical engineering application;The damping effect of asymmetric coating is slightly better than that of symmetric coating,but the difference is minimal;the damping effect of locally coated passively constrained damping beam increases with the thickness of the confinement layer and weakened with the increase in the thickness of the viscoelastic layer.