Finite element model for damping optimization of viscoelastic sandwich structures

In this work a simple and efficient finite element model is used for the damping optimization of multilayer sandwich plates, with a viscoelastic core sandwiched between elastic layers, including piezoelectric layers. The elastic layers are modeled using the classical plate theory and the core is modeled using Reddy’s third-order shear deformation theory. The finite element formulation is obtained by assembly of N “elements” through the thickness, using specific assumptions on the displacement continuity at the interfaces between layers. The free vibration response of damped multilayer sandwich structures is characterized by solving an eigenvalue problem to obtain the fundamental natural frequency and corresponding modal loss factor. The optimization is conducted in order to maximize the fundamental modal loss factor, using gradient based algorithms, and afterwards, considering steady state harmonic motion the analysis is conducted in time domain to obtain the structure response. The model is applied in the solution of some illustrative examples and the results are presented and discussed.