Assessment of plate elements on bending and vibrations of composite structures

This article assesses classical and refined finite plate elements on bending and vibrations of layered composites and sandwich structures. To this purpose, recent authors' findings have been extended to dynamics. About 20 plate finite elements have been implemented and compared: classical ones based on displacement assumptions are compared to advanced mixed elements which are formulated on the basis of Reissner's mixed variational theorem. Finite elements which preserve the independence of the number of independent variables from the numbers of the N-l layers (equivalent single-layer models) as well as those elements in which the number of the unknown variables remains N-l-dependent (layer-wise models) are both considered. Linear up to fourth-order expansions in the thickness direction are treated for the unknown stress and displacement variables. Sandwich beams and cross-ply as well as angle-ply composites plates have been analyzed. Simply supported as well as clamped edges have been considered. Finite-element results have been implemented and compared, where available, to analytical closed form solutions. Mostly the fundamental circular frequency has been used as a test bed to assess the whole implemented multilayered elements.