长横担输电塔的风致效应研究
发布时间：2018-09-18 20:35
【摘要】：为节省线路走廊,近年来长悬臂输电塔得到了广泛应用。此类塔型刚度小,横担层数多且长度较大,风效应复杂。其结构的高柔特性导致风荷载成为设计的主控荷载。 目前大部分输电塔风振数值分析都是基于标准边界层风场进行的,对于多回路长悬臂塔型在台风风场与标准边界层风场下风振响应的差异鲜有涉及。以沿海地区某四回路长悬臂角钢输电塔为原型建立了有限元模型,采用谐波叠加法生成两类风场下的风速时程,并在时域内进行了输电塔风振响应和风振系数的数值分析。台风风场的高湍流特性导致其作用时各测点的顺风向风振响应均大于B类风场下的对应值。两类风场下,输电塔的风振系数比值约为l.25。因此,台风多发地区的输电塔设计须考虑台风高湍流引起的动力风荷载增大效应。 由于长悬臂塔型的节段绕流效应复杂,通过气弹模型风洞试验来寻找结构的不利风致效应,是对抗风设计理论计算的补充和改进。以上述长横担角钢输电塔为原型,通过气弹模型风洞试验考察结构的气动失稳趋势及薄弱部位,并结合数值分析进行了抗风加强措施研究。塔头部位由于不利的气固耦合效应,在高风速下出现了较明显的弯扭耦合振动现象；塔身下部长斜材在风振激励下,产生局部振动,易引发构件的压弯破坏。分别采取增强塔头斜材和增设横隔面等措施对原结构进行抗风加强设计,后续试验结果和理论计算均表明整塔的极限承载能力得到提高。 同时,长悬臂输电塔具有横担水平长度大的特性。来流紊流易引起风压分布的不对称,同时塔头构造复杂,构件周围特征湍流明显,会产生一定的动态扭转风荷载。以沿海地区某500kV某长悬臂钢管输电塔为研究对象,基于HFFB试验和频域理论分析,得到了来流不均匀和构件周围特征湍流引起的扭转气动力。结果表明在进行长悬臂输电塔设计时,应同时考虑来流风压不均匀以及特征湍流产生的扭转效应的影响。
[Abstract]:In order to save line corridor, long cantilever transmission tower has been widely used in recent years. This type of tower has a small stiffness, a large number of layers and a large length, and the wind effect is complex. The flexibility of the structure results in the wind load becoming the main control load of the design. At present, most numerical analysis of wind vibration of transmission tower is based on standard boundary layer wind field, and the difference of wind vibration response of multi-loop long cantilever tower under typhoon wind field and standard boundary layer wind field is seldom involved. The finite element model of a four-circuit long cantilever angle steel transmission tower in coastal area is established. The wind speed time history under two kinds of wind field is generated by harmonic superposition method. The wind vibration response and wind vibration coefficient of transmission tower are analyzed numerically in time domain. Due to the high turbulence characteristics of typhoon wind field, the downwind vibration response of each measuring point is larger than the corresponding value of B type wind field. Under two kinds of wind field, the ratio of wind vibration coefficient of transmission tower is about 1. 25. Therefore, the increasing effect of dynamic wind load caused by typhoon turbulence should be taken into account in the design of transmission towers in typhoon prone areas. Because of the complex flow around the section of long cantilever tower, the wind tunnel test of Aeroelastic model is used to find the unfavorable wind-induced effect of the structure, which is a supplement and improvement to the calculation of anti-wind design theory. Taking the long cross-pole angle steel transmission tower as the prototype, the aerodynamic instability trend and weak position of the structure were investigated by wind tunnel test with the Aeroelastic model, and the measures to strengthen the wind resistance were studied in combination with the numerical analysis. Due to the unfavorable gas-solid coupling effect at the head of the tower, the bending-torsional coupling vibration appears at high wind speed, and the inclined material under the tower body produces local vibration under the wind vibration, which can easily lead to the compression and bending failure of the members. The wind-resistant strengthening design of the original structure is carried out by means of strengthening the tower head oblique material and adding the transverse plane respectively. The results of subsequent test and theoretical calculation show that the ultimate bearing capacity of the whole tower has been improved. At the same time, the long cantilever transmission tower has the characteristics of large horizontal length. It is easy to cause asymmetry of wind pressure distribution due to incoming turbulence. At the same time, the structure of tower head is complicated and the characteristic turbulence around members is obvious, which will result in certain dynamic torsional wind load. Taking a long cantilever steel tube transmission tower of 500kV in coastal area as the research object, based on the HFFB test and frequency domain theory analysis, the torsional aerodynamic force caused by uneven incoming flow and characteristic turbulence around the member is obtained. The results show that in the design of long cantilever transmission tower, the influence of non-uniform wind pressure and torsional effect caused by characteristic turbulence should be taken into account at the same time.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU347;TU312.1
本文编号：2249036
[Abstract]:In order to save line corridor, long cantilever transmission tower has been widely used in recent years. This type of tower has a small stiffness, a large number of layers and a large length, and the wind effect is complex. The flexibility of the structure results in the wind load becoming the main control load of the design. At present, most numerical analysis of wind vibration of transmission tower is based on standard boundary layer wind field, and the difference of wind vibration response of multi-loop long cantilever tower under typhoon wind field and standard boundary layer wind field is seldom involved. The finite element model of a four-circuit long cantilever angle steel transmission tower in coastal area is established. The wind speed time history under two kinds of wind field is generated by harmonic superposition method. The wind vibration response and wind vibration coefficient of transmission tower are analyzed numerically in time domain. Due to the high turbulence characteristics of typhoon wind field, the downwind vibration response of each measuring point is larger than the corresponding value of B type wind field. Under two kinds of wind field, the ratio of wind vibration coefficient of transmission tower is about 1. 25. Therefore, the increasing effect of dynamic wind load caused by typhoon turbulence should be taken into account in the design of transmission towers in typhoon prone areas. Because of the complex flow around the section of long cantilever tower, the wind tunnel test of Aeroelastic model is used to find the unfavorable wind-induced effect of the structure, which is a supplement and improvement to the calculation of anti-wind design theory. Taking the long cross-pole angle steel transmission tower as the prototype, the aerodynamic instability trend and weak position of the structure were investigated by wind tunnel test with the Aeroelastic model, and the measures to strengthen the wind resistance were studied in combination with the numerical analysis. Due to the unfavorable gas-solid coupling effect at the head of the tower, the bending-torsional coupling vibration appears at high wind speed, and the inclined material under the tower body produces local vibration under the wind vibration, which can easily lead to the compression and bending failure of the members. The wind-resistant strengthening design of the original structure is carried out by means of strengthening the tower head oblique material and adding the transverse plane respectively. The results of subsequent test and theoretical calculation show that the ultimate bearing capacity of the whole tower has been improved. At the same time, the long cantilever transmission tower has the characteristics of large horizontal length. It is easy to cause asymmetry of wind pressure distribution due to incoming turbulence. At the same time, the structure of tower head is complicated and the characteristic turbulence around members is obvious, which will result in certain dynamic torsional wind load. Taking a long cantilever steel tube transmission tower of 500kV in coastal area as the research object, based on the HFFB test and frequency domain theory analysis, the torsional aerodynamic force caused by uneven incoming flow and characteristic turbulence around the member is obtained. The results show that in the design of long cantilever transmission tower, the influence of non-uniform wind pressure and torsional effect caused by characteristic turbulence should be taken into account at the same time.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU347;TU312.1
【参考文献】
相关期刊论文 前10条
1 屈成忠;刘春玲;李霞;张有佳;;500kV猫头塔结构动力特性分析[J];东北电力大学学报(自然科学版);2008年06期
2 陈隽,徐幼麟,李杰;Hilbert-Huang变换在密频结构阻尼识别中的应用[J];地震工程与工程振动;2003年04期
3 甘凤林;杨振伟;代晓光;;基于谐波合成法的输电塔线体系风致响应分析[J];电网技术;2009年18期
4 谢强;管政;严承涌;;1000kV输电塔横风向振动风洞试验研究[J];电网技术;2011年05期
5 张琳琳;谢强;李杰;;输电线路多塔耦联体系的风致动力响应分析[J];防灾减灾工程学报;2006年03期
6 楼文娟,孙炳楠;风与结构的耦合作用及风振响应分析[J];工程力学;2000年05期
7 白海峰;李宏男;;大跨越输电塔线体系随机脉动风场模拟研究[J];工程力学;2007年07期
8 谢强;阎启;李杰;;横隔面在高压输电塔抗风设计中的作用分析[J];高电压技术;2006年04期
9 谢强;丁兆东;赵桂峰;李杰;;不同横隔面配置方式的输电塔抗风动力响应分析[J];高电压技术;2009年03期
10 刘锡良,周颖;风荷载的几种模拟方法[J];工业建筑;2005年05期
，本文编号：2249036
本文链接：https://www.wllwen.com/kejilunwen/sgjslw/2249036.html
