Formulation of a three-dimensional shear-flexible bimaterial beam element with constant curvature

This paper presents the closed-form formulation for a three-dimensional curved beam element with round bimaterial section. The formulation includes the effects of shear forces on displacements and stresses and of the beam curvature on the distribution of bending and torsional stress over the cross section. The element is coherent with the well-known theory for straight beams, which is obtained exactly as the curvature radius becomes infinite. The numerical predictions for a test case compare favourably with published analytical and experimental results and with the outcome of a purposely developed, large-scale FE brick model.