Free vibration analysis of composite plates

A series of plate elements, based on the modified complementary energy prin cipal, are developed to study the free undamped vibration response of lamin ated composite plates. The Mindlin thin plate theory is selected to govern the general characteristics and behavior of these plate elements. A series of in-plane strain functions are assumed from which the corresponding in-pl ane strains and corresponding stresses for each lamina are determined. The transverse stresses are then computed by satisfying the equations of the eq uilibrium. Eight-noded isoparametric elements are utilized to describe the displacement field. These hybrid plate elements are used to form the stiffn ess and the consistent mass matrices. The fundamental natural frequencies a re the computed by solving the generalized eigenvalue problem and their app lication demonstrated via a number of examples. [S0094-9930(00)02603-7].