Damping Characteristics of Laminated Thick Plates

Abstract

We develop the analysis for the exact three-dimensional viscoelastic solution for simply supported, thick multilayered composite plate strips. Each layer is assumed to possess monoclinic or higher material symmetry and to be perfectly bonded to adjacent layers. The damping capacity, or loss factor, of the composite plate is derived using energy principles, allowing analysis of arbitrary through-the-thickness geometry for the composite plate. The damping characteristics of the composite plate, as well as its natural modes of vibration, are obtained with the aid of the matrix transfer technique. The matrix transfer method simplifies the requisite analytical developments as well as speeding the numerical calculations. While our analysis treats general material anisotropy and arbitrary through-the-thickness geometry, we examine, as special cases of our analysis, constrained layer damping treatments and sandwich plates. We compare our solution with previous well-known solutions that rely on complex bending modulus formulations and isotropic materials in simple layered treatments. The modal damping capacity of the composite plate is investigated as a function of both frequency of vibration and as a function of material damping modulus.