Abstract: It is of great importance that obtaining the effects of frequency dependent characteristic on the vibration of viscoelastic composite structure during the dynamic modeling and vibration reduction design. On the basis of introducing the mechanical parameters appropriately, the dynamic model of viscoelastic composite structure under base excitation is established considering the frequency dependent characteristic and the formulas of solving the natural characteristics and vibration response are obtained. Furthermore, the thin cantilever titanium plate attached the viscoelastic damping material is chosen and an experiment is performed to verify the rationality of the developed method. Finally, using the model, the effects of frequency dependent characteristic on the vibration of viscoelastic composite plate are analyzed for the thin plate attached two kinds of different viscoelastic materials. They can be presented as follows. When calculating the natural frequencies and the non-resonances, the frequency dependent characteristic of viscoelastic material can be neglected. While solving the modal loss factors and the resonance responses of composite structure, the frequency dependent characteristic of viscoelastic material needs to be considered. If the frequency dependent characteristic is not included in the model, the results corresponding to the average values of viscoelastic parameters in the considered frequency range are more closed to the results obtained by considering the frequency dependent characteristic.

Key words: analysis of the effects, base excitation, frequency dependent characteristic, vibration characteristics, viscoelastic composite structure