Prestressed stayed beam–columns under eccentric compression: Behaviour and prestress optimization

For prestressed stayed beam–columns, the structural behaviour and optimization method under eccentric compression are investigated numerically. The eccentric compression usually occurs when there exist installation errors, or when the member takes both the axial load and end moment. The indicators to quantify structural efficiency and failure mode are defined, and they together with load-carrying capacity of the stayed member with different structural configurations and prestress distributions are studied. The results reveal, for the first time, that when the short crossarm and eccentricity are located on the same side of the main member, the behaviour of the prestressed stayed beam–column under eccentric compression can be divided into small and large eccentricity zones owing to the different failure modes, such as compression dominant and bending dominant modes. Moreover, different optimization methods for the structural configuration and prestress distribution in the different zones are determined by striking a balance between maximizing load-carrying capacity and structural efficiency. This work would provide suggestions for the design of the prestressed stayed beam–columns under eccentric compression and the eccentric tolerance in installation.