特高压超高铁塔的稳定性研究
发布时间：2018-08-24 10:00
【摘要】：本文以镇江某大跨越塔-线体系为背景工程,输电塔高度为198m,跨越距离约1200m。输电塔所处环境较为复杂,受到荷载主要有风荷载、重力荷载、地震荷载、覆冰荷载等,针对输电塔等高耸结构而言,对结构稳定产生影响的因素主要是由风荷载作用。本文在已有成果的基础上对跨越塔的风荷载响应进一步进行非线性分析研究,针对背景工程进行了输电塔对比选型,利用大型有限元分析软件ANSYS对塔及塔-线体系建模,进行考虑P-△效应的情况下输电塔和塔-线体系的动力特性分析及在动力特性分析的基础上利用现有理论的等效静力法分析输电塔的风荷载响应,按照弹性屈曲失稳模式的分析方法对塔体的使用阶段进行分析获得弹性屈曲的安全系数及结构屈曲模态和失稳构件的破坏形式,建立结构的非线性分析模型分析研究铁塔及塔-线体系极限承载力。单塔模型模态分析结果显示结构的第一阶振型为横向振动即为结构体系最容易发生失稳时荷载方向,利用施加风荷载进行弹性屈曲分析的结果同时引入结构3‰的初始缺陷、材料的非线性本构模型进行考虑大变形的非线性屈曲分析。结果显示在结构屈曲以铁塔根部主材最先达到材料的屈服应力开始,通过跟踪结构最高点的荷载-位移关系,在风速达到68m/s时结构整体失稳,在考虑风速脉动的情况下,结构的极限承载力降低。通过导线应力控制对塔-线体系进行找形然后进行动力特性和考虑结构二阶效应的屈曲分析,由于导线属于柔性结构其存在对体系中其他部分产生耦合作用影响,结构体系的振动周期相对单塔增加约27.6%、体系的极限承载力相对单塔降低至48m/s。
[Abstract]:Based on a large span tower-line system in Zhenjiang, the transmission tower height is 198 m and the span distance is about 1 200 m. The transmission tower is located in a complex environment, which is mainly subjected to wind load, gravity load, earthquake load, ice load and so on. For tall structures such as transmission towers, the main factors that affect the stability of the structure are wind loads. In this paper, based on the existing achievements, the nonlinear analysis of the wind load response of the span tower is carried out, and the comparison and selection of the transmission tower for the background engineering are carried out, and the tower and the tower-line system are modeled by using the large-scale finite element analysis software ANSYS. The dynamic characteristics of transmission tower and tower-line system are analyzed under the consideration of P- effect, and the wind load response of transmission tower is analyzed by using the equivalent static method of existing theory on the basis of dynamic characteristic analysis. According to the analysis method of elastic buckling failure mode, the safety factor of elastic buckling, the buckling mode of structure and the failure mode of unstable members are obtained by analyzing the use stage of tower body. The nonlinear analysis model is established to analyze the ultimate bearing capacity of tower and tower-line system. The results of modal analysis of single tower model show that the first vibration mode of the structure is transverse vibration, that is, the direction of load when the structure system is most vulnerable to instability. The results of elastic buckling analysis under wind load are used to introduce the initial defect of the structure of 3 鈥，
本文编号：2200469
[Abstract]:Based on a large span tower-line system in Zhenjiang, the transmission tower height is 198 m and the span distance is about 1 200 m. The transmission tower is located in a complex environment, which is mainly subjected to wind load, gravity load, earthquake load, ice load and so on. For tall structures such as transmission towers, the main factors that affect the stability of the structure are wind loads. In this paper, based on the existing achievements, the nonlinear analysis of the wind load response of the span tower is carried out, and the comparison and selection of the transmission tower for the background engineering are carried out, and the tower and the tower-line system are modeled by using the large-scale finite element analysis software ANSYS. The dynamic characteristics of transmission tower and tower-line system are analyzed under the consideration of P- effect, and the wind load response of transmission tower is analyzed by using the equivalent static method of existing theory on the basis of dynamic characteristic analysis. According to the analysis method of elastic buckling failure mode, the safety factor of elastic buckling, the buckling mode of structure and the failure mode of unstable members are obtained by analyzing the use stage of tower body. The nonlinear analysis model is established to analyze the ultimate bearing capacity of tower and tower-line system. The results of modal analysis of single tower model show that the first vibration mode of the structure is transverse vibration, that is, the direction of load when the structure system is most vulnerable to instability. The results of elastic buckling analysis under wind load are used to introduce the initial defect of the structure of 3 鈥，
本文编号：2200469
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