ABSTRACT
The formulae in Chapters 8 and 9 involve the use of certain geometric properties of the cross-section. In steel design these are easy to find, since the sections used are normally in the form of standard rollings with quoted properties. In aluminium, the position is different because of the use of non-standard extruded profiles, often of complex shape. A further problem is the need to know torsional properties, when considering lateraltorsional (LT) and torsional buckling. The following quantities arise:
(a) Flexural S Plastic section modulus; I Second moment of area (inertia); Z Elastic section modulus; r Radius of gyration.
