【摘要】 大跨越输电塔-线体系是一种复杂的空间塔线耦联体系,体系动力特性计算中由于导、地线的振型密集,输电塔的振型难以辨清。在对大跨越输电塔-线体系的动力特性研究中,采用白噪声激励体系,得到输电塔耦合了导、地线的响应;利用振动模态识别技术,可得到输电塔耦合了导、地线的低阶模态。以多条输电线路工程中不同类型、不同高度输电塔为原型,建立空间有限元模型,利用振动模态识别技术提取出大跨越输电塔-线体系中塔架结构的第1自振周期及其振型,得到适用于大跨越酒杯塔和大跨越干字型塔的第1周期近似计算公式。对工程实例的仿真分析表明,该公式能比较准确地反映大跨越输电塔-线体系的动力特性,值得推广应用。更多还原

【Abstract】 The transmission tower and conductor system is a complicated 3-dimensional tower-line coupling vibration system.Analytical data indicate that it is very hard to identify the vibration modes of transmission towers due to the denseness of vibration modes of conductors and grounds.In order to establish an accurate vibration mode of the transmission tower coupling with cables,the time-history response of the tower was acquired through application of the white-noise wave system.The vibration modal identification technology was adopted in frequency-domain to identify the effects of vibration mode of tower-cable coupling system.In this paper,A 3-dimensional finite element model was established respectively for several transmission towers of different types and various heights,and the their natural vibration periods and vibration modes of the tower structure in the tower-line system were obtained by use of the vibration modal identification technology.Based on the above results,an approximate formula was developed for estimation of the natural period,which is applicable to the cup-tower and the self-supported tower carrying two circuits on the same structure.A simulation case study shows that this formula can well reflect the dynamic characteristics of the tower-line system,and is worth application.更多还原