Abstract
Free vibration of laminated antisymmetric angle-ply annular circular plates are studied with inclusion of first order shear deformation theory using a spline function approximation by applying a point collocation method. The equations of motion of the plates are derived using first order shear deformation theory. The vibration of two- and four-layered plates are analysed, made up of two types of materials and two types of boundary conditions. A generalized eigenvalue problem is obtained and solved numerically for obtaining the required eigenfrequency parameters and associate eigenvectors are spline coefficients. The stability of the annular circular plate is analyzed with respect to the radii ratio, circumferential node number, different materials, number of laminates, ply orientations under different boundary conditions for two and four layered plates.