【作者】 赵庆斌；

【导师】 刘学信；

【作者基本信息】 西南交通大学 ， 桥梁与隧道工程， 2004， 硕士

【摘要】 本文对送电铁塔结构的类型、构造特点、荷载性质进行了介绍，对压杆的稳定理论和极限荷载理论计算方法进行了阐述。送电铁塔杆件单角钢压杆的极限承载力，是压杆稳定理论问题中极值点稳定问题，极值点失稳的理论计算属于非线性结构分析的范畴，很难用解析求解，通常用数值分析的方法求得数值解。本文用数值分析的方法，按《架空送电线路杆塔结构设计技术规定》(DL／T 5154-2002)定义的6种杆端边界条件，即：两端中心受压、一端中心另端偏心受压、两端偏心受压、一端有约束、两端有约束、两端无约束，应用ANSYS软件，对一端有约束、两端无约束和两端有约束边界条件下，初始弯曲、残余应力、初始偏心、安装误差、尺寸误差5种杆件缺陷分别对极限承载力的影响进行了有限元分析，求出了相应的极限承载力。 由计算知，截面的几何尺寸误差对单角钢压杆的极限承载力影响是最大的，但这恰恰是目前被国内设计规范(规定)所忽略的。 在两端无约束情况下，找出两种最不利的影响因素进行组合，算出相应的φ值曲线。根据已求得的极限承载力，采用Perry型公式，求公式参数α，并求出α=α(λ)，从而得到φ=φ(λ)。 一端有约束和两端有约束情况，通过修正长细比kλ得到φ。 经过比较，本文提出的φ值曲线与《钢结构设计规范》的差-2％～22％，与《架空送电线路杆塔结构设计技术规定》的差-19.1％～4.8％，介于两个规范(规定)之间。更多还原

【Abstract】 In this thesis, an introduction was made on the types and structural properties of power transmission steel towers. Specific loads acting on these structures were also discussed. Then the theory of stability and critical load calculation procedures were investigated. The actual ultimate compressive capacity of the angle irons in a transmission tower structure could be found through nonlinear structural analysis according to theory of compressive member stability. This problem can hardly be solved analytically. However, there are numerical methods to get the answer. In this thesis the critical loads for members with different structural considerations were calculated numerically with FEM software ANSYS. According to "Technical Specifications for Power Transmission Towers" (DL/T5154-2002), six types of load and boundary conditions were investigated, they were: perfectly centered compression at both ends, eccentricity at one end, eccentricity at both ends, rotation constrain at one end, both ends and none. Also included in the analysis was the consideration of initial imperfection of the members, such as initial deflection, residual stress, imperfect centered loading, manufacture imperfection and workmanship.It is concluded from the results that the geometrical imperfection of the cross section has most influence on the compression critical loads. However, this factor is not taken much into account in current Codes and Specifications.For members free of rotation at both ends, two most weakening factors of the members were combined and the values calculated. By applying the critical loads to Perry formula, coefficient a was found as a function of slenderness ratio X . Then could also be represented as a function of λ(w=w (λ) ).For the rotation constrained cases (constrained at one end or both ends), was obtained by the amendment of slenderness ratio as k λ .The comparison of the results revealed that the curve of value obtained from the study showed about -2% ~ 22% discrepancy from the curve in the "Code for Design of Steel Structures" and -19.1% - 4.8% from "Technical Specifications for Power Transmission Towers". The final results lay between those indicated by thetwo specifications.更多还原