Cross-section design

Abstract

During loading of the structure, cross-sections of structural members are subjected to internal forces and moments. This chapter provides the design resistances of cross-sections to individual internal forces and moments and their combinations. It starts with axial tension, where design resistances are given for cross-sections with or without holes and goes to the compression resistance of sections, accounting for possible local buckling effects. It then presents the elastic and plastic bending resistance, depending on the cross-section class, and the resistance to shear forces. Torsion and its uniform and non-uniform mechanisms with the corresponding design resistances are described. The properties and main characteristics in respect to torsion are given for open and hollow sections. Elastic and plastic resistances to St Venant and warping torsion are determined. Subsequently, cross-section design to combined internal forces and moments is given. Elastic design is expressed in terms of limitation of the von Mises stresses. For plastic design, interaction relations between internal forces and moments are defined including biaxial bending and axial force as well as shear forces and torsion. Interaction relations for plastic design of I-, H-, rectangular or circular hollow sections and angle sections as proposed by Eurocode 3 or derived by the authors are presented.