Variational Approximate and Mixed-Finite Element Solution for Static Analysis of Laminated Composite Plates

The main objective of the present study is to give a systematic way for the derivation of laminated composite plates by using the mixed type finite element formulation with a functional. The fırst order shear deformation plate theory is used. Differential field equations of composite plates are derived from virtual displacement principle. These equations were written in operator form then by using the Gateaux differential method, a new functional which including the dynamic and geometric boundary conditions is obtained after provide potential conditions. Applying mixed­type finite element based on this new functional, a plate element namely FOPLT32 is derived which have 8 degrees of freedoms on per node, total 32 freedoms. The reliability of the derived FOPLT32 plate elements for static analysis is verifıed, since the results obtained have been shown to agree well with the existing ones.