In-plane bucking and nonlinear elastic theories of PS (Pre-stressed) beams subject to not only compression induced by a tendon cable but also to external forces are newly formulated. The system consists of a simply supported/cantilever steel beam, a straight cable with constant eccentricity, anchorages, and multiple deviators. In particular, the effects of having either un-bonded or bonded deviators on the elastic buckling and nonlinear behavior of the PS beam are rigorously investigated. To achieve this, buckling and second-order analysis theories of PS systems with no deviator, one deviator, and multiple deviators are derived in non-dimensional form. In addition, stability and large displacement problems of the simple/cantilever beam system are analytically solved while considering the effect of deviators. In order to verify the validity of the proposed theories, numerical examples for PS systems are given and the results compared with FE analysis results from ABAQUS models. The results show that deviators restrain flexural deformation of beams that have buckled under the initial tension very strongly so that the system’s buckling strength is greatly improved. Particularly, it is found that the critical buckling loads of simple and cantilever PS systems due to initial tension are equal when the number of deviators is identical.

新制定了PS（预应力）梁的面内屈曲和非线性弹性理论，不仅承受了钢缆的作用，而且还受到了外力的作用。该系统由一个简单的支撑/悬臂钢梁，一个偏心率恒定的直电缆，锚固和多个偏斜器组成。特别地，具有未结合的或结合的偏斜的影响严格研究了PS梁的弹性屈曲和非线性行为。为此，以无量纲形式导出了不带偏斜，一个偏斜和多个偏斜的PS系统的屈曲和二阶分析理论。另外，在考虑偏斜器影响的同时，通过解析解决了简单/悬臂梁系统的稳定性和大位移问题。为了验证所提出理论的正确性，给出了PS系统的数值例子，并将结果与​​ABAQUS模型的有限元分析结果进行了比较。结果表明，偏斜器非常有效地抑制了在初始拉力作用下弯曲的梁的挠曲变形，从而大大提高了系统的屈曲强度。特别，