ABSTRACT
Planar bracing is commonly used, although the major exception is the bracing in space frames, which generally lies in several planes. Internal bracing for torsion on a rectangular tower is covered later in this chapter. Lateral restraint bracing is generally added at one or two cladding rail and purlin locations, designed for a force equal to 1% of the maximum factored force in the compression flange of the member, divided equally between the points of restraint. Plain round rods are often used to support cladding rails or purlins at quarter or one third span points in order to limit bending stress or deflection in the weak axis. However, at the present time it has generally been found more practical and economic to compromise between modular units and the space frame concept, using standard modules to build space frames. The design of most space frames is carried out by computer.
