Parametric study of dynamic response of sandwich plate under moving loads

Constrained layer damper is widely used in engineering applications to suppress the severe vibration of structural systems, especially for the cases with moving loads, such as sandwich beam or sandwich plate. The response analysis and parametric analysis of these sandwich structures under moving loads have not still understood comprehensively. To do this, a hybrid approach based on extended Rayleigh-Ritz solution together with penalty method and differential quadrature method is presented to predict the dynamic responses of sandwich plate with isotropic face plate and a viscoelastic core subjected to moving loads. Both the energy terms related to the sandwich plate and the energy terms introduced by boundary conditions are derived based on the first order shear deformation theory (FSDT) and expressed using the Rayleigh-Ritz solutions, and then the governing equation of motion of sandwich plate is obtained through Lagrange equation, which can model a sandwich plate with various boundary conditions. Different with classical Rayleigh-Ritz solutions, the admissible functions adopted here is a set of combination of simple polynomials and trigonometric functions, which just satisfy a totally unconstrained boundary condition, and penalty method is applied to handle constraints. Then the variations of the natural frequency, associated modal loss factor and vibration response with the parameters (such as thicknesses of constrained layer and damping layer, elastic modulus of constrained layer material, and shear modulus and loss factor of damping layer material) of sandwich plate are studied. Moreover, the variations of maximum dynamic deflections with different boundary conditions as well as moving speeds are investigated.