A LAMINATED COMPOSITE BEAM ELEMENT SEPARATELY INTERPOLATED FOR THE BENDING AND SHEARING DEFLECTIONS WITHOUT INCREASE IN NODAL DOF

Abstract

A finite element suitable for the analysis of composite frames is proposed based on the first-order shear deformation theory. The deflection is separately interpolated for the bending and shearing with the cubic and linear functions respectively, which is then projected into the nodal displacements. The projection matrix is constructed by using the equilibrium equation, and a force and displacement relation. The error due to the projection is zero for symmetric laminates and unsymmetric cross-ply laminates, but some error occurs for general laminates and unsymmetric angle-ply laminates. With an increase in the number of elements, this error becomes zero. Since no extra nodal degrees of freedom are introduced, standard assembly procedure is made possible. No shear locking occurred in this method. Examples are solved in order to show the effectiveness of this beam element in the analysis of laminated composite beam structures in comparison with other elements.