ANALYTICAL AND EXPERIMENTAL INVESTIGATIONS OF PRESTRESSED LAMINATED COMPOSITE BEAMS WITH CONSTRAINED VISCOELASTIC DAMPING LAYER

The damping characteristics of prestressed composite beams with constr ained viscoelastic damping layers on one surface of the beam are inves tigated both analytically and experimentally. The analytical method in volves derivation of finite element equations for the analysis of beam and plate structural elements with continuous or discontinuous constr ained viscoelastic damping layer with prestress. The experimental meth od is an impulse-frequency response technique which is used on preload ed laminated beams. Results for loss factors and natural frequencies o f [90/90/0/90/90] and [90(3)/0(3)/90(3)]s T300/934 graphite-epoxy lami nated beams with a 3M SJ-2052X constrained viscoelastic tape attached on one surface are presented. Numerical results based on the finite el ement prediction agree reasonably well with the experimental results u nder different tensile and compressive preloads.