Dynamic analysis and experiment of viscoelastic damped sandwich plate
WANG Hui-cai, ZHAO De-you (Department of Naval Architecture, Dalian University of Technology,Dalian 116024, China)
The dynamic analysis of damped sandwich plate is done by numerical computation and experiment.The damped sandwich plate element is developed on the basis of minor distortion and linear elasticity hypothesis.The three layer is taken as the Mindlin plate element,the finite element model is established in the local coordinate system that is based on the median plane of each layer,the eccentricity matrix is considered,which make the program more simple.The constant complex module of viscoelastic material is used to calculate the frequency and loss factor of the sandwich pate by the complex eigenvalue method.The effects of the thickness, module, loss factor of viscoelastic material on the dynamic behavior of the structure are discussed.Some valuable results for engineering application were obtained.Also the modal experiment and response experiment of monolayer plate,unconstrained damped plate and constrained damped sandwich plate are done and the damp of structure is identified.The results show that the FEA method is reliable and relatively accurate.Also a numerical method to compute the dynamic response of viscoelasic damped sandwich plate under harmonic excitation is presented in this paper. The viscoelastic material is regarded as elastic material and its damp is regarded as viscous damp.The modal damp got from the experiment is used to calculate the damp coefficient and the direct integration method is used.The response under harmonic excitation is computed and compared with the test result.Results indicate that this simplified method is valid.A simple method is given for the approximate computation in engineering.
【CateGory Index】： TB535.1