A numerical and experimental investigation of steel beams damped with constrained viscoelastic layers /

Damping of steel beams with constrained viscoelastic layers is studied in both the frequency and time domains. Cantilevered steel beam specimens with various configurations of constrained viscoelastic layers are experimentally and analytical subjected to random frequency vibrations, spike inputs, and large finite rotations A frequency dependent shear modulus is used to express the viscoelastic material behavior in the frequency domain, and a Prony series representation of the shear relaxation modulus is used for time domain simulations. The simulated response converges using approximately five Prony terms in the series. Increase in damping from one to two layers of constrained viscoelastic treatment and the detrimental effect of a discontinuous constrained viscoelastic treatment is observed experimentally. Predicted responses obtained using the proposed finite element model exhibit similar trends. Natural frequencies and damping factors obtained from linear and nonlinear time domain finite element analyses are found to be in good agreement with experimental results