Compression members are one of the basic structural elements and are described by the terms ‘columns’, ‘stanchions’ or ‘struts’, all of which primarily resist axial load.
Columns are vertical members supporting floors, roofs and cranes in buildings. Though internal columns in buildings are essentially axially loaded and are designed as such, most columns are subjected to axial load and moment. The term ‘strut’ is often used to describe other compression members such as those in trusses, lattice girders or bracing. Some types of compression members are shown in Figure 7.1. Building columns will be discussed in this chapter and trusses and lattice girders are dealt with in Chapter 8.