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 hypothesis, a beam theory is formulated in terms of in-plane elastic properties to analyze composite I and channel section pultruded beams which includes the transverse shear deformation of the beam cross section. The importance of the shear influence on the total vertical deflection is reported. Symmetric lay-up composite beams result in a bending-twisting structural coupling. The optimal fibre orientation for minimizing vertical displacements and twist angle is also investigated.