输电铁塔应力测试实验研究

发布时间：2017-12-31 01:20

本文关键词：输电铁塔应力测试实验研究　出处：《广西大学》2015年硕士论文　论文类型：学位论文

【摘要】：输电线路(塔)是电力工业系统的大动脉,研究其结构内力情况,保证其安全、可靠、稳定运行是关系国计民生的重大问题。鉴于铁塔实际结构形状、受载及变形等比较复杂,采用理想化、简化结构模型等方法进行分析校核比较困难,且得出的结果可能与工程实际不符合的情况。本文研究某送变电公司SJ331A-18双回路塔和2B-GJ31-18单回路塔的应力测试方法,评价SJ331A-18型塔在各种载荷工况下的应力变化特征。本文的研究成果及结论如下：1.根据《架空线路杆塔结构荷载试验》DL/T899-2012要求,制定合理、安全的实验加载步骤和方法；结合铁塔实际运行情况确定了符合工程实际的4种模拟实验工况：正常运行工况、模拟覆冰15mm工况、断线工况和破坏工况；在此基础上计算给出了各工况、各百分比所需的加载载荷。2.进行应变片防水、防潮实验。实验结果表明,石蜡合剂防护层在户外高温日晒时会溶化流失,失去对应变片的保护作用；而采用三防漆防护,在模拟野外长达30天高温日晒、水潮浸袭等条件下,应变片绝缘电阻500MΩ,即使将测点直接浸入水中,也不会发生零飘等问题,且三防漆的使用比石蜡合剂更方便。3.进行应变片测量时效性和加载可重复性实验。实验结果表明,采用三防漆进行防护的应变片,在模拟野外高温日晒、水、潮浸袭等条件下,30天之内得到的测量结果与理论计算值最大相差4.4%,重复加载时最大相差4.3%；能够满足户外长时应力测试要求。4.进行输电铁塔应力测试。测试铁塔塔高分别为36.6m、27.5m,两塔跨度73.32m,塔身共布置96个应变测点,挂有48条模拟荷载拉线；如此大规模同步、实时群测在广西尚属首例。实验中,通过采用三防漆解决了应变片长时防护问题；通过自制拉力计连接应变仪解决了拉线荷载同步、实时监控问题；通过采用分组群测,降低导线长度及合理布线等消除了工频、静电及地电干扰等问题。5.铁塔测试结果表明,正常荷载工况下,双回路塔最大应力出现在第二层横担下方主材上,为满载压应力179.1MPa,远小于设计值31 OMPa；覆冰加载到75%时,此处应力仍然最大,为压应力290.33MPa,超过了其计算稳定许用值275.199MPa；表明铁塔第二层横担下方的主材是整个结构的薄弱环节,在设计和运行维护中要重点关注。
[Abstract]:Transmission line (tower) is the main artery of the electric power industry system, study the structure internal force, ensure its safe, reliable and stable operation is of great significance. In view of the actual structure is beneficial to the people's livelihood tower shape, loading and deformation is more complex, the idealized and simplified structure model analysis and checking is difficult. The results may be related to engineering practice does not meet the situation. This paper studies the stress test method of a power transmission company SJ331A-18 Double Circuit Tower and 2B-GJ31-18 single circuit tower, SJ331A-18 tower in the evaluation of various loading conditions. The stress characteristics of research results and conclusions of this paper are as follows: 1. according to the requirements of the overhead line load test of >DL/T899-2012 tower structure reasonable, experimental steps and methods of loading safety; combined with the actual operation of the tower was determined 4 kinds of simulation experiments and practical conditions In normal operating conditions, the simulation of ice break condition and 15mm condition, the failure condition; on the basis of this calculation are given in different working conditions, the percentage of.2. load required for strain gauge waterproof, moisture-proof experiment. Experimental results show that the wax mixture protective layer in the outdoor temperature on the sun will melt loss, lose corresponding protective effect change sheet; and the use of three paint protection, in the simulation field up to 30 days of high temperature water tide sun, invasion and other conditions, the insulation resistance strain gauge 500M, even if the measuring point is directly immersed in water, does not occur zero drift and other issues, and the use of three paint than paraffin mixture more convenient.3. measurement time loading and repeatability of the experiment strain. The experimental results show that the strain gauge has a conformal coating for protection, in the simulation field high temperature sun, water, tide invasion and other conditions, the measurement results obtained within 30 days and the theoretical The maximum value is 4.4%, the maximum difference between the repeated loading 4.3%; can meet the test requirements of outdoor long time stress.4. transmission tower stress test tower tower are respectively 36.6m, 27.5m, the two tower span 73.32m, the tower is arranged 96 strain measuring point, hanging 48 simulation load pull; synchronization such a large-scale, real-time monitoring is the first case in Guangxi. In the experiment, by using the conformal coating to solve the protection problem when using the self-made film strain; strain gauge tension meter connection solves the load pull synchronization, real-time monitoring; by means of grouping group measurement, reduce the wire length and reasonable wiring to eliminate static electricity and electrical power, some problems in.5. tower test results show that the normal load conditions, double the maximum stress appears in the second layer below the main cross arm, for the full stress 179.1MPa, far less than the design value of 31 OMPa; icing Loading to 75%, the maximum stress is compressive stress, 290.33MPa, exceeds the allowable value of 275.199MPa stability calculation show that the second layer tower; the cross arm below the principal is the weak link of the whole structure, to focus on design and operation and maintenance.

【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM753

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