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

A finite element suitable for the analysis of composite frames is prop osed based on the first-order shear deformation theory. The deflection is separately interpolated for the bending and shearing with the cubi c 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 erro r due to the projection is zero for symmetric laminates and unsymmetri c cross-ply laminates, but some error occurs for general laminates and unsymmetric angle-ply laminates. With an increase in the number of el ements, this error becomes zero. Since no extra nodal degrees of freed om are introduced, standard assembly procedure is made possible. No sh ear locking occurred in this method. Examples are solved in order to s how the effectiveness of this beam element in the analysis of laminate d composite beam structures in comparison with other elements.