Shear–bending–torsion elastic interaction diagrams in circular steel sections

Interaction diagrams are extensively used as a tool for designing prismatic members subjected to several combined stresses. For a long time, sets of these diagrams have been available in building technologies, such as reinforced concrete, steel and composite sections, under various stresses. This paper shows the analytical formulation to obtain the diagrams corresponding to bending and torsion simultaneously acting on steel circular cross-sections in combination with shear force. In particular, a detailed analysis of the interaction elastic limit surface is carried out for stresses acting on circular sections. Ó