Prestressed Lattice Frames with Intersecting and Offset Diagonals

Abstract

Prestressed lattice structures are structures in which certain components are pretensioned in order to improve the performance of the structure. Prestressing the diagonals of lattice frames can increase the lateral stiffness and load‐carrying capacity by increasing the rotational restraint at the joints. Thus, the objective of this research was to determine the effect of prestressing the diagonals on the buckling load of lattice frames with intersecting and offset diagonals. A total of seven tests were conducted on two‐dimensional, single‐bay, three‐story frames with nonprestressed and prestressed diagonals and with intersecting and offset diagonals. A theoretical study of the frames was also conducted. It was found that prestressing the diagonals in frames with intersecting diagonals did not increase the load‐carrying capacity. Offsetting the diagonals on the crossarm or on the verticals increased the load‐carrying capacity over that obtained for similar frames that were not prestressed.