Effects of in-plane loads on free vibration of symmetrically cross-ply laminated plates resting on Pasternak foundation and coupled with fluid

The aim of present work is to investigate the effects of uniform in-plane loads on vibratory characteristics of symmetrically cross-ply laminated composite plates on elastic foundation and vertically in contact with fluid based on the first order shear deformation theory. The fluid is assumed to be ideal, incompressible and inviscid with small amplitude motion and the effects of hydrostatic pressure and free surface waves are negligible. The fluid domain is considered to be finite in depth and width but it is infinite in length direction. The Rayleigh-Ritz method is applied to derive the eigenvalue equation of the fluid-plate system and Chebyshev polynomials multiplied by a boundary function are adopted as the admissible functions in the procedure. The accuracy of the proposed method is examined via comparison studies with the available data in the literature. The effects of different parameters on natural frequencies such as, thickness-span ratios, aspect ratios, fluid depth ratios, load intensities, elastic foundation coefficients and various types of in-plane loads and boundary conditions are discussed in tabular and graphical forms.