Vibrations of layered viscoelastic beam with interlayer slips

Two methods for calculating both eigenfrequencies and the logarithmic decrement for layered beams with interlayer slips and consisting of viscoelastic stiffness-comparable layers have been presented in this paper. The hybrid method described in Section 4 is a new one since formulation of the boundary value problem considered has been derived in the new way i.e., by linking different kinematical patterns within adjacent layers. The second method presented in Section 2 has been derived within the linear theory of (visco)elasticity as a result of modification of the formulation (that is interlayer continuity conditions) given by Karczmarzyk (1993). Both the methods have been applied to investigation of influence of the interlayer slips on eigenfrequencies and vibration damping of two- and three-layer beams.