Vibration and Thermal Analysis and Optimum Design of Viscoelastic Sandwich Beam

Sandwich beam structures have many applications in various fields of engineering including especially in aerospace and transportation industries. Using the viscoelastic material as the core layer in these structures, one could include significant amount of damping with minimum impact on the total mass of the structure. In the current study, vibration damping analyses of the sandwich beam structure using the finite element formulations are presented. These formulations are developed based on the linear and non-linear displacement fields in the viscoelastic core layer. Results obtained from the present study were compared with those reported in literature and it is shown that the non linear displacement field exhibits more accurate damping response than the linear model. Parametric sensitivity analysis has been carried out to show the damping behavior of partially treated sandwich beam under different configuration. Genetic algorithm is utilized in finding the optimum configuration to achieve the highest damping. Results show that for damping behavior of beam with the clamped-clamped boundary condition, the partially treated beam structure is more effective than the fully treated one. Also the effect of the heat dissipation in the damping layer of the beam on the damping performance of the viscoelastic material is investigated under the steady-state harmonic excitation. The generated heat has been taken into the consideration by implementing the finite difference formulation based on the irregular grids. Results obtained clearly indicate that the temperature gradient developed in the structure and hence the amplitude of the response increases after every cycle