Studies Of The Coupled Thermoelastic Vibration For The Axially Moving Viscoelastic Sandwich Structure

Viscoelastic damping sandwich structures are widely used in aircraft and other fields because of it’s high strength, light quality, vibration and noise reduction, especially it’s smooth surface and excellent aerodynamic configuration. With the increase of the velocity, Aerodynamic heating phenomenon is serious, in this case, the problems of the thermoelastic vibration in the high speed structures have attracted much attention. The viscoelastic sandwich structures in the high velocity aircraft can be modeled as axially moving continuum system, whose dynamic behavior variety under the coupled thermoelastic situation, so it’s very meaningful to research the dynamic behavior of this kind of structures. In this thesis, the dynamic characteristics of the viscoelastic sandwich structure with axially moving speed under the coupled thermoelastic are mainly studied.l)The axially moving viscoelastic damping sandwich beamBased on the Kelvin viscoelastic model, Considering the interaction of the material deformation and the heat conduction, the vibration equations of the axially moving beam with partial sandwich layer are derived;on this basis,the coupled governing equations of the axially moving viscoelastic sandwich beam are derived with the theory of small deformation.The influence of axially speed, thermoelastic, thermal expansion and heat conduction on the sandwich beam is researched using the Galerkin truncation method; The exciting load, which is consist of temperature function and external harmonic excitation force, of the equations is interpolated by a quadratic polynomial of time, then the vibration equation is solved by the method of Galerkin and the displacement is obtained, in every small time by using the numerical method of iteration and convergence to solve heat conduction equation, the temperature is gained, and the influences of the axially moving speed and thermal loading duration on the response of the structureswith heat impulse acting on the upper surface are studied.when the heat impulse and external load are acting on the different surface,the sandwich beam’s vibrating responses in two directions are analysised.2)The axially moving viscoelastic damping sandwich plateBased on the Kelvin viscoelastic model, Considering the interaction of the material deformation and the heat conduction, the coupled governing equations of the axially moving viscoelastic sandwich plate are derived with the theory of small deformation. With the method applied to solve the beam’s response in prior chapter, extended from two dimension to three dimension, the response and temperature field distribution of the sandwich plate are solved. The effect of axially moving speed, sandwich damping, parameters about the thermal load on the plate’s response are discussed.