Nominal Flexural Strength of Thin-walled Steel Girders with Deviators Pre-stressed by Rectilinear Cables

This study proposes a design method for calculating the nominal flexural strength of pre-stressed (PS) mono-symmetric thin-walled steel beam/girders. How to evaluate the flexural strength of conventional steel beam/girders without cables is first summarized, referring to AISC specification. A closed-form solution for LTB of PS girders with deviators under end moments is next mentioned, and a new method to calculate the yield, elastoplastic, and plastic moments of the PS girders is presented. Then, a procedure for determining the nominal strength of the PS steel beam/girders having discretely installed intermediate deviators depending on the laterally unsupported length is presented. Finally, an extensive study is conducted to explore the nominal strength of the PS system by varying the eccentricity, width, and initial pre-stressing force. The results demonstrate that the pre-stressing technique can result in a stiffer and more economical steel girder.