The Effect of Anisotropy on Free Vibration of Rectangular Composite Plates with Patch Mass

In this paper, the effect of anisotropy on the free vibration of laminated rectangular plate supporting a localized patch mass is investigated. The two variable refined plate theory is applied to define the third order displacement field of a composite rectangular plate. The plate is considered to have simply supported boundaries. The equations of motion for rectangular plate are obtained by calculus of variation. Parametric study of non-dimensional natural frequencies is carried out and the influences of geometrical parameters such as aspect ratio of the plate, size and location of the patch mass on these frequencies are also studied. First, the results obtained are compared with those reported using several plate theories. In the next step, the effect of anisotropy on free vibration of plates for different types of lamination are studied. The numerical results are found to be in a very good agreement with well known published papers for the case of vibration analysis of loaded and unloaded plates.