Vibration Analysis Of Axially Moving Viscoelastic Sandwich Plate

Viscoelastic damping sandwich structures are widely used in mechanical transmission, aerospace vehicle, high-speed trains, weapon industry because of its high strength, light quality, vibration and noise reduction, smooth surface and excellent aerodynamic configuration. Viscoelastic damping sandwich structures of mechanical transmission are modeled as axially moving continuum structure, there are rich dynamic behavior of the axially moving system. At supersonic or hypersonic speed, aircraft-structure made by viscoelastic damping material which are subjected inertia force, elasticity force, thermal load, flutter analysis is one of important subject, axially moving and panel flutter are mainly research. So in this article the viscoelastic damping sandwich plate are mainly researched from axially movement and flutter.1) Axially moving viscoelastic damping sandwich systemBased on the theory of von Karmen thin plate with large deflection and Kelvin-Viogt material constitutive law, the controlling equation which dominates the transverse vibration of the axially moving viscoelastic sandwich plate was established. Four sides simply supports are considered. The nonlinear partial differential equation is transformed into a set of nonlinear ordinary differential equations through a Galerkin approach. The linear and nonlinear systems are researched respectively. For linear system of the partial differential equation, the eigen equation is obtained by using Galerkin method. One-mode and two-mode eigen equations are obtained by using1-term and2-term Galerkin truncation. The influence of the ratio of the core and axially moving velocity on the transverse vibration characteristic were discussed. For nonlinear system, also One-mode and two-mode nonlinear equations are obtained by using1-term and2-term Galerkin truncation. The number of the equilibrium point along with the axially moving velocity and the dynamic stability are discussed. The bifurcations are considered by using numerical simulations. The evolvement of bifurcation diagrams of transverse vibration of this system varying with the axially moving velocity is investigated. The interesting dynamic behavior is observed by employing the method of phase portrait, Poincare maps, power spectrum diagram and enlargement of the bifurcation diagram. 2) Supersonic viscoelastic damping sandwich systemBased on the theory of von Karmen thin plate with large deflection and Kelvin-Viogt material constitutive law, the controlling equation which dominates the flutter vibration of the viscoelastic sandwich panel was established. Four sides simply supports are considered. The nonlinear partial differential equation is transformed into a set of nonlinear ordinary differential equations through a Galerkin approach. The linear and nonlinear system are researched respectively. For linear system of the partial differential equation, the eigen equation are obtained by using Galerkin method. One-mode and two-mode eigen equations are obtained by using1-term and2-term Galerkin truncation. The influence of viscoelastic damping coefficient on the fluttering characteristic is discussed, as well as dynamic pressure and ratio of core layer which is expressed as thickness of core layer divides constraint layer’s; For nonlinear system, also One-mode and two-mode nonlinear equations are obtained by using1-term and2-term Galerkin truncation. The number of the equilibrium point along with flow speed and the dynamic stability are discussed. The bifurcations are considered by using numerical simulations. The evolvement of bifurcation diagrams of transverse vibration of this system varying with the flow speed is investigated. The interesting dynamic behavior is observed by employing the method of phase portrait, Poincare maps, power spectrum diagram and enlargement of the bifurcation diagram.