Lateral–torsional buckling of steel beams pre-stressed by straight tendons with a single deviator

Abstract

We develop a novel lateral–torsional buckling theory for pre-stressed (PS) steel H-beams with or without a deviator by using the total potential energy derived from the second order terms of semi-tangential rotations, the analytically derived exact solutions are presented and compared with the approximate solutions produced by the Ritz method and FEM. In this work, we particularly focus on the buckling characteristics of simple and cantilever PS beams under three loading conditions: initial tension only, compression, and quasi/semi-tangential moments. In addition, we demonstrate how these quasi- and semi-tangential moments are generated based on semi-tangential rotations. Furthermore, we verify that in-plane load distributions and spatial buckling loads under the conditions of a rectilinear cable with an un-bonded deviator are exactly the same as under the conditions of a rectilinear cable with a bonded deviator. Finally, a deviator’s effect on the buckling strengths of the PS system with double tendons under external loading is examined.