ملخص
Natural Frequencies of Orthotropic Circular Plate using Wittrick-Williams' AlgorithmDr.Nihal ELkaabazi , nihalkabazi@yahoo.comUniversity Of TripoliCircular plates are used for the most engineering fitting .The common examples are Table tops, Manhole cover, Turbine disks and Tank bottoms. Orthotropic plate is defined as a plate which has different material properties in mutually perpendicular direction. Wittrick-Wiiliams' Algorithm have been used for finding the natural frequencies for several paper for beams, portal frames and shells before. In this paper ,the Dynamic stiffness matrix of orthotropic plate have been derived from the Forth order plate differential equation by transforming it into ordinary differential equation, and finding the unknown using the boundary value solver COLSYS .The Algorithm in this paper has been used to find the Natural frequencies of plates.The results of the Natural frequency will be compared with other published paper on circular plate. A study of several orthotropic ratios will