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。
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.
引文
[1]陈海波,李振福.西北电网750kV输变电工程关键技术研究——杆塔方案及荷载研究[R].北京:国电电力建设研究所,2002.
[2]廖宗高,张华,陈海波.特高压输电线路设计风速取值的探讨[J].中国电力,2006,27(4): 28-32.
[3]万建成,李清华.1000k V级交流输电系统大跨越工程技术的研究[R].北京:国网北京电力建设研究院,2006.
[4]李茂华.Q 420和Q460高强钢在输电线路铁塔应用的研究[R].北京:国网北京电力建设研究院,2006
[5] GB 50017-2003,钢结构设计规范[S].北京:中国计划出版社,2003.
[6] DL/T 5154—2002,架空送电线路杆塔结构设计技术规定[S].北京:中国电力出版社,2002.
[7] Loads and Resistance Factor Design Specification for Structural Steel Buildings [S].American institute of steel construction, inc. Chicago,1999.
[8] Design of Latticed Steel Transmission Structures,ASCE 10-90[S].
[9] JEAC 6001-2000,日本架空送电规程[S].
[10]赵熙元.建筑钢结构设计手册[M].北京:冶金工业出版社,1995.
[11] GBJ 17-88,钢结构设计规范[S].北京:中国计划出版社,1988.
[12] GB/T 1591-94,低合金高强度结构钢[S].中国标准出版社,1994.10.
[13]张东英,刑海军.Q460高强钢在1000kV杆塔上应用研究[R].北京:国网北京电力建设研究院,2007.11.
[14]柏拉西.金属结构的屈曲强度[M].科学出版社,1965.1-25.
[15]郭月青.等边角钢和T型截面轴压杆弹塑性弯扭屈曲临界力分析[D].1998. 25-33.
[16] Bjorhovde,R..Deteministic and Probabilistic Approaches to the Strength of Steel Columns[J]. Ph.D.Dissertation,Department of Civil Engineering,Lehi University,Bethlehem,PA,1972
[17] Gal ambos,T.V.ed.Guide to Stability Design Criteria for Structures[J].4nd.Ed.Johri Wiley and Sons,1988.
[18] Beedle,L.S.(Editor-in-chief).Stability of Metal Structures-A World View[J].2nd. Ed.U.S.A.,1991.
[19] Stinteso,D.ed.European Convention of Constructional Steelworks Manual on the Stability of Steel Structures[J].2nd.Ed..ECCS,Paris,1976.
[20] R.narayanan.Axially Compressed Structures Stability and Strength.Applied Science Publishers London and New York[J].1982,181-216.
[21] C.J.Earls.On the Notion Effective Length for Single Angle Geometric Axis Flexure[J]. Journal of Constructional Steel Research,2002,Vo1.58,1195-1210.
[22] A.zureick.Design Strength of Concentrically Loaded Single Angle Struts.Engineering Journal[J].1993,No.1,17-20.
[23] Seshu adhava Rao Adluri,Murtyk. s.madugula.Eccentrically Loaded Steel Single Angle Struts. Engineering Journal[J].1992,No.2,59-66.
[24]中华人民共和国建设部.钢结构设计规范((TJ17-74)[S].北京:中国计划出版社,1974.
[25]李开禧等.钢压杆的柱子曲线[J].重庆建筑工程学院科技资料,1983,Vol.83,1-30.
[26]李开禧等.逆算单元长度法计算单轴失稳钢压杆的临界力[J].重庆建筑工程学院学报,1982,No.4,26-29.
[27]沈祖炎,胡学仁.单角钢压杆的稳定计算[J].同济大学学报,1982,No.3,56-71.
[28]曹平周.角钢组合下型截面轴心压杆弯扭失稳承载力研究[J].钢结构,1998,Vo1.13,No.1,3-6.
[29]陈骥.单轴对称截面轴心受压构件弯扭屈曲设计问题[J].钢结构,1999,Vol.14,No.4,49-52.
[30]陈骥.钢结构稳定理论与设计(第一版)[M].科学出版社,2001,226-237.
[31]郭耀杰.钢结构稳定设计[M].武汉大学出版社,2003.
[32]夏志斌,潘有昌.钢结构稳定理论[M].高等教育出版社,1988.
[33]任伟新,曾庆元.钢压杆稳定极限承载力分析[M].中国铁道出版社,1994.
[34]查杰斯著.结构稳定理论原理[M].唐家祥译.甘肃人民出版社,1982.
[35]陈绍蕃.钢结构设计原理[M].科学出版社,1998,90-100.
[36]陈骥,钢结构稳定理论与设计(第三版)[M].北京:科学出版社,2006.
[37]陈绍蕃.钢结构[M].中国建筑工业出版社,1994,288-298.
[38]陈绍蕃,钢结构稳定设计指南[M].中国建筑工业出版社,1994.
[39]吕烈武等.钢结构构件稳定理论[M].中国建筑工业出版社,1983,205-216.
[40]魏明钟,钢结构(第二版)[M].武汉:武汉理工大学出版社,2002.
[41]魏巍,对梁柱分析中变形增量计算模型的评述[J].重庆建筑大学学报,1999.2.
[42]李开禧,须宛明.钢梁-柱中两杆端变形增量的相关方程[J].重庆交通学院学报,1989.8.
[43]李开禧、肖允徽,单向偏心弹塑性压杆临界力计算[J].重庆建筑工程学院学报,1981.
[44]童根树,钢结构的平面外稳定[M].中国建筑工业出版社,2006.
[45]陈绍蕃.角钢剖分T型钢压杆的弯扭屈曲[J].钢结构,2000,Vol.15,No,4.
[46]《送电线路单角钢中心受压压力曲线》铁塔主角钢部分试验报告[R].电力工业部电力建设研究所,1981.4.
[47]《送电线路铁塔交叉斜材部件试验报告》[R].电力工业部电力建设研究所,1981.10.
[48]《送电铁塔压杆稳定计算方法探讨》[J].国家电力公司西南电力设计院,2001.2.
[49]《不等边角钢偏心受压试验》[R].默增禄、耿景都,《电力建设研究所》,2001.7.
[50]陈健.冷成型单角钢轴压杆稳定性能研究[D].西安建筑科技大学,2004.
[51]刘丽敏.高强钢在特高压输电塔中的应用[D].同济大学,2007.
[52]《送电线路铁塔单角钢—节点板系统稳定性试验研究报告》[R].吴骁、胡涵洵,电力建设研究所,1984.12.
[53]顾石川.热轧单角钢轴心受压构件整体稳定性能研究[D].西安建筑科技大学,2004.
[54]赵庆斌.送电铁塔单角钢受压极限承载力研究[D].西南交通大学,2004.
[55]王国周.关于残余应力对钢压杆承载能力影响的研究成果在钢结构规范中的应用[J].冶金建筑,1981,No.10,15-22.
[56]王国周.残余应力对钢压杆承载能力的影响及理论分析概况[J].冶金建筑,1981,NO.9,15-9.
[57]王国周.钢结构残余应力分布的若干特点[J].冶金建筑,1981,No.8,31-35.
[58]何远宾.输电线钢塔的有限元分析与研究[D].2002.
[59]. ANSYS Theory Reference[J].ANSYS,Inc.,ANSYS5.7,2001.
[60]. ANSYS Element Reference[J].ANSYS,Inc.,ANSYS5.7,2001.
[61]. Basic Analysis Procedures Guide[J].ANSYS,Inc.,ANSYS5.7,2001.
[62]. Structural Analysis Guide[J].ANSYS,Inc.,ANSYS5.7,2001.
[63]. T.V.Galambos,Guide to Stability Design Criteria for Metal Structures[J].John Wiley&Sons, Inc.,1998.
[64]张胜民,基于有限元软件ANSYS7.0的结构分析[M].北京:清华大学出版社,2003.
[65]尚晓江,邱峰等,结构有限元高级分析方法与范例应用[M].北京中国水利水电出版社,2005.
[66]李浩月等.ANSYS工程计算应用教程[M].中国铁道出版社,2003.
[67]嘉木工作室.ANSYS 5.7有限元实例分析教程[M].机械工业出版社,2002.
[68]美国ANSYS公司北京办事处.ANSYS非线性分析指南[M].1998.
