Shear strain effects on flexure and torsion of thin-walled pultruded composite beams

The paper presents a theoretical study on the static structural response of thin-walled composite open-section beams. Based on a Vlasov-type linear hy pothesis, a beam theory is formulated in terms of in-plane elastic properti es to analyze composite I and channel section pultruded beams which include s the transverse shear deformation of the beam cross section. The importanc e of the shear influence on the total vertical deflection is reported. Symm etric lay-up composite beams result in a bending-twisting structural coupli ng. The optimal fibre orientation for minimizing vertical displacements and twist angle is also investigated.