ANALYSIS OF LAMINATED BEAMS WITH A LAYER-WISE CONSTANT SHEAR THEORY

Based on generalized laminate plate theory, the formulation of a one-d imensional beam finite element with layer-wise constant shear (BLCS) i s presented. The linear layer-wise representation of in-plane displace ments permit accurate computation of normal stresses and transverse sh ear stresses on each layer for laminated beams with dissimilar ply sti ffnesses. The BLCS formulation is equivalent to a first-order shear de formation beam theory (Timoshenko beam theory) on each layer. For the accurate computation of interlaminar shear stresses, the layer-wise co nstant shear stresses obtained from constitutive relations are transfo rmed into parabolic shear stress distributions in a post-processing op eration described in detail. The accuracy of the BLCS element is demon strated by solving several numerical examples reported in the literatu re. While retaining the simplicity of a laminated beam theory, the ele ment predicts results as accurate as much more complex elasticity anal yses, and it is suitable to model frame-type structures.