黏弹性夹芯复合材料圆柱壳自由振动特性分析OA

This paper establishes a unified model for predicting the free vibration and loss factor of the rotating cylindrical shell and cylindrical shell panel for viscoelastic sandwich composite cylindrical shell structures.Based on the first-order shear deformation and sawtooth theory,the coupling relationship between the displacement fields of each layer of the structure is obtained,and the virtual spring technique is introduced to simulate the physical boundary constraints and the internal coupling relationship of the revolving cylindrical shell.The displacement field is expanded using two-dimensional first-order Chebyshev polynomials,and the Rayleigh-Ritz method is used to determine the natural frequencies and loss factor.After verifying the correctness of the model by comparing it with some publications and the finite element method,the influence of material parameters is analyzed.The results show that the constraint layer and base layer both use the[0,θ,0]paving scheme.When approaches 90°,the fundamental frequency and its modal loss factor will reach a minimum value;increasing the stiffness ratio of the base layer and the constrained layer will increase the natural frequency of the cylindrical shell,but the increase in the stiffness ratio of the base layer leads to a greater increase in the natural frequency than that of the constrained layer;by increasing the stiffness ratio of the constraining layer while maintaining the stiffness ratio of the base layer constant,the loss factor of the fundamental frequency mode of the cylindrical shell decreases.Conversely,by increasing the stiffness ratio of the base layer while maintaining the stiffness ratio of the constraining layer constant,there is little change in the loss factor of the fundamental frequency mode of the cylindrical shell.