Free vibration of doubly-curved generally laminated composite panels with viscoelastic matrix

Abstract

As a first endeavor, this study scrutinizes the effects of general lamination schemes on the natural frequencies and loss factors of simply supported doubly-curved laminated composite panels. Transversely isotropic fibers obey linear elastic rule while isotropic polymeric matrix follows both standard solid and Kelvin-Voigt viscoelastic models. Frequency-dependent properties are obtained by multi-cell micromechanical approach and Alfrey correspondence principle. The governing equations of motions with frequency-dependent shear-stretching, bending-stretching and bending-twisting couplings are derived using Hamilton principle and third-order shear deformation theory. The coupled PDEs of motions are figured out via Galerkin method and eigenvalue solver. To verify, vibrational characteristics are compared with available results of elastic laminated panels and viscoelastic sandwich plates. Then, the effects of constitutive relations, fiber volume fraction, different fibers, geometrical parameters, symmetric, anti-symmetric and asymmetric laminations schemes are investigated on vibrational characteristics of spherical, cylindrical and hyperboloid panels. Also, crossing phenomenon and curve veering of frequencies and loss factors are observed.