The Analyses for Natural Frequency of Laminated Plate Using an Improved Higher-Order Theory

An improved higher order method was used in calculating the natural frequency of laminated composite plate. The function of equation of free vibration of laminated plate was established using Hamilton's principle and calculated the natural frequencies of plates. The influence of the laying-angle and thickness ratio and cross-elastic modulus ratio to the frequency of the plate were analyzed. It is shown that the natural frequency of antisymmetric angle-ply laminated plates and antisymmetric cross-ply laminated plate can be calculated by using this paper theory; in addition, it is feasible to calculate the natural frequency of the random form of laying laminate.