Stability of Cable-stayed Masts in Tensioned Fabric Structures

Stayed-columns or masts have found application in both flexible and rigid structures. They are used in tensioned fabric structures as the principal compression members to provide equilibrium to the high tension forces from fabric membrane and cables. The stiffness of stayed-masts has to be large enough to overcome instability due to buckling. As such, the transformation of a tube section by adding cross-arms and prestressed stays substantially increases the load-carrying capacity of tall and slender masts.

The use of cables, the presence of prestress and inherent nonlinearities, all contribute to the intricate behaviour of stayed masts. For some stayed masts, the anti-symmetric (or two-lobe) mode may govern design, which is uncharacteristic when compared to regular column design. There is still a lot to be learned and recognized about their behaviour. By understanding their behaviour, structural designers can benefit from using these lightweight compression members with enhanced stiffness. This paper reveals their unique structural characteristics using a single cross-arm mast as example.