Curved beams with circular cross-sections under pure in-plane bending

This paper deals with the phenomenon of flattening or inflation of cross-sections caused by pure bending on beams of hollow circular cross-section with or without initial curvature. Both initially straight and initially bent tubes are analyzed under in plane bending. Results over a wide range of initial curvature values are presented. Finally, the area of validity of the expressions used is studied, as well as the deformations and stresses that occur in practice.