摘要: Prestressing with external tendon is one of the most efficient techniques for the strengthening of steel structures and for controlling the structure deflection.This technique can be used for new structures as well as for rehabili... 展开 Prestressing with external tendon is one of the most efficient techniques for the strengthening of steel structures and for controlling the structure deflection.This technique can be used for new structures as well as for rehabilitation of existing structures.Three-dimensional nonlinear finite-element analyses have been performed in this paper to investigate the prestressing effects on the flexural behavior and the structural response of prestressed simply supported steel I-beam with external unbonded tendon.ANSYS software has been used to analyze and simulate the process of applying the prestressing force and the structure loads.Geometrical imperfections and buckling modes of the unloaded beam were taken into consideration as an initial condition.This paper consisting of verification study on existing experimental results to obtain that the finite-element model conduct by ANSYS can simulate the behavior of prestressed steel beam and shown good agreement with the existing experimental results and parametric study to investigate the effect of several parameters; in terms of the number of deviator,eccentricity of the external tendon,prestressing technique,type of loading and effect of initial imperfection; on the structure behavior.The effect of bracing has been considered after applying the presstressing force to the tendon at the top flange and the bottom flange of the steel beam “at service”.The results show that these factors must be considered in the design because they have a great effect on the stability and the flexural behavior of the prestressed steel structure. 收起