【作者】 刘盼；

【导师】 李正良；

【作者基本信息】 重庆大学 ， 固体力学， 2008， 硕士

【摘要】 随着我国电力需求的不断增长,电网技术的持续进步,输电线路铁塔向大型化发展。长期以来,我国输电线铁塔所用钢材局限于Q235和Q345两种强度等级。和国外先进国家相比,我国输电杆塔结构所用的钢材种类少、强度值偏低、可选择余地小。当杆塔荷载较大时,只能采用组合截面来弥补材料强度低的不足,增大了设计、加工的工作量。高强钢具有强度高、承载能力强的特点,采用高强钢是有效缓解上述矛盾的措施之一。在输电线路铁塔中使用高强钢,既有明显的技术经济效益,又有利于提高我国输电线路的建设水平。本文主要研究的对象是高强等边角钢Q460。为确保将高强等边角钢Q460合理安全地应用于输电线路铁塔上,本文对Q460高强等边单角钢L125x10进行了5组不同长细比的轴心受压试验研究,以及对Q460高强等边单角钢L140x12进行了3组不同长细比的偏心受压试验研究。试验表明,该试验装置构造合理,符合实际要求。同时,分析了影响该角钢极限承载力的因素,并且把试验结果与现行《架空送电线路杆塔结构设计技术规定》DL/T 5154—2002规范和美国《输电铁塔设计导则》的计算结果相比较,绘出相应的λ? ?柱子曲线。本文根据试验分析结果对规范公式做一些细微的调整,提出Q460高强等边角钢的在轴心受压和两端偏心受压下的长细比修正系数。最后采用有限元分析软件ANSYS对Q460高强等边单角钢L125x10、L140x12压杆建模进行稳定性分析。考察Q460高强等边角钢在轴心受压和两端偏心受压下的破坏形态和极限承载力,并且将ANSYS的分析结果和试验结果对比分析。通过试验和有限元方法的研究结果表明,可以发现一般来说,轴心受压构件在长细比较小时,容易发生弯扭失稳破坏,而在长细比较大时,容易发生弯曲失稳破坏。而且ANSYS计算结果和试验结果吻合较好。更多还原

【Abstract】 As the demand for electric electricity is increasing and the power grid technology is upgraded constantly, the scale of transmission towers becomes larger in our country. The steel of domestic transmission towers has been limited to two kinds of strength grades, Q235 and Q345. for a long time, Compared with the steel in advanced countries, the species of the domestic steel is few, its strength value is low and the room for choice is small. When the tower load is heavier, composite section can only be used to make up for the lack of low-strength materials, which increases the workload of designs and machinings. However, the characteristics of high-strength steels are high strength and strong bearing capacity. So, utilizing high-strength steels in transmission towers is one of effective measures to relax the contradiction above, which not only produce the technical and economic efficiency but also promote the construction level of transmission lines in our country.The study object in this paper is high-strength equilateral-angle steel member of Q460. To ensure that high-strength equilateral angles Q460 are applied to transmission towers reasonablly and safely, the test studies on the high-strength equilateral-angle steel members are carried out in this paper, which include L125x10 axial compressed tests of 5 groups of different slenderness ratios and L140x12 eccentric compressed tests of 3 groups of different slenderness ratios. The test results indicate that the design for the test devices are reasonable and meet the actual requirements. Meanwhile, the factors that effect on the ultimate bearing capacity of the angle steel are analyzed. The test data are compared with the calculation results of“Technical Regulation of Design for Towers and Pole Structure of Overhead Transmission Line”(DL/T 5154-2002) and ASCE. The column curve ofλ? ? is also painted. According to the analysis of test results, some adjustment for the code formula are made, and the slenderness-ratio correction coefficient of Q460 high-strength equilateral-angle steel member in cases of axial and eccentric compression are put forward.Finally, the stability of high-strength equilateral-angle steel compressed bar of Q460 L125x10、L140x12 is analyzed with the finite element analysis software ANSYS. The failure mode and ultimate bearing capacity under axial compression and eccentric compression are studied. The results of ANSYS are also compared with the test results. By means of tests and numerical analysis, it can be found that in the case of axial compression, the flexural-torsional buckling failure is liable to happen when the slenderness ratios is small, and the flexural buckling failure usually occurred when the slenderness ratios is large. ANSYS calculation results agree well with the test results.更多还原