Mathematical Analysis of Transmission Line Vibration
TL;DR: In this paper, the response of stranded cables to exciting forces produced by wind is studied, and details of an analytical and experimental study of cable self-damping are presented, as well as an experimental model for self-deployment.
Abstract: The response of stranded cables to exciting forces produced by wind is studied here, and details of an analytical and experimental study of cable self-damping are presented.
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TL;DR: The nonlinear passive isolation is effective for wide frequency bandwidth than the linear isolation system and the nonlinear energy harvesting system shows a great scope to harvest energy from wide ranges of excitations.
Abstract: Vibration present on various levels in many engineering fields and hence vibration mitigation has become a subject of intense study. The nonlinear vibration isolation devices are effective for broad frequency bandwidth and can provide better vibration isolation than linear devices. The need for nonlinearity in stiffness and damping characteristics has motivated researchers to apply the nonlinearity found in mechanisms or materials in the passive vibration control devices. This review discusses the applications of nonlinearity in the passive vibration control devices to provide an understanding of how the nonlinearity is applied and useful in the implemented system. Further, applications for nonlinearity can also be extended in the energy harvesting devices, Nonlinear energy sink, metamaterials for the purpose of vibration isolation and energy harvesting. The need for nonlinearity also encouraged research work through inspiration from the nature called bio-inspired devices. The bio-inspired devices mimic the nonlinearity of the biological system to suppress the vibrations. The nonlinear passive isolation is effective for wide frequency bandwidth than the linear isolation system. Further, the nonlinear systems also reduce transmissibility much efficiently than the linear system. The nonlinear energy harvesting system shows a great scope to harvest energy from wide ranges of excitations. The bio-inspired devices also are proven to be effective in vibration isolation. Additionally the design of the metamaterial with nonlinearity in the microstructure, proves to be promising in the vibration suppression applications. Based on the review, the nonlinearity introduced into the systems has greater benefits than the linear systems.
78 citations
TL;DR: In this article, a theoretical analysis of the response characteristics of the Stockbridge dampers is presented, and the experimental results of the analysis have been verified experimentally by treating it as a two-degree-of-freedom system.
45 citations
TL;DR: In this article, a combination of an impedance transfer technique (ITT) and a forced vibration method (FVM) is proposed for analyzing the Aeolian vibration of a span of a single conductor with multiple dampers.
Abstract: A novel algorithm is developed in this paper for analyzing Aeolian vibration of a span of a single conductor with multiple dampers. The algorithm is characterized by a combination of an impedance transfer technique (ITT) and a forced vibration method (FVM). The ITT avoids singularities that may occur due to a conductor's very low bending stiffness with respect to its tension. On the other hand, the FVM can easily handle non-proportional damping (which is typical for the problem in concern) without having to solve a complex eigenvalue problem. In addition, the algorithm can easily accommodate a conductor's terminal flexibility as well as a damper's rotational effect that may exist due to its possible asymmetry. The algorithm is very efficient so that solution is almost instantaneous for most analysis problems. The algorithm has recently been implemented into a commercial Aeolian vibration analysis and design software-EPRI Vibration version 3.0.
38 citations
Cites background or methods from "Mathematical Analysis of Transmissi..."
...A conductor’s sag may be neglected due to the relatively high frequency range that is of interest [7]....
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...These approaches include ones based on electrical-mechanical analogy [3], wave propagation [4]–[6], summation of assumed modes [7]–[9], matrix transfer [10], dynamic stiffness [11], integral transformation [12], etc....
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...The conductor is treated as a taut (tensioned) beam so that a conductor’s bending stiffness is taken into account [5], [7]–[11]....
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TL;DR: Similarity laws governing the internal damping of stranded cables in transverse vibrations are based on the assumption of hysteretic loss factor associated with the flexural rigidity of the cable and the assumption that this loss factor is the same for all cables of the same construction.
Abstract: Similarity laws governing the internal damping of stranded cables in transverse vibrations are based on the assumption of hysteretic loss factor associated with the flexural rigidity of the cable and the assumption that this loss factor is the same for all cables of the same construction. These laws are derived from the basic cable differential equation. The proportionality factors, the exponents of the various parameters in the laws, are obtained from the experimental results of a typical member of a family of similar cables. The same set of laws has been found to apply very well to ACSR (aluminum conductor steel reinforced) conductors having the same number of strands and fairly well to all ACSR conductors. Other families of cables, such as ACAR (aluminum conductors aluminum reinforced), steel cables, etc., could each have their own set of similarity laws, which would all look alike. >
33 citations
TL;DR: In this article, tuneable vibration absorbers (TVAs) are used to suppress galloping forced vibrations (as a semi-active control approach) using mode summation technique, mathematical model of the hybrid problem including the transmission line and an arbitrary number of absorbers is presented.
32 citations
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41 citations
01 Jan 1956-Transactions of The American Institute of Electrical Engineers. Part Iii: Power Apparatus and Systems
TL;DR: In this article, the authors used an electrical-mechanical analogies to determine how the characteristics of vibration dampers should be related to the tension, weight per foot, and diameter of conductors on which the dampers are mounted, for optimum damping of aeolian vibration.
Abstract: Impedance matching relationships, based on electrical-mechanical analogies, are used to determine how the characteristics of vibration dampers should be related to the tension, weight per foot, and diameter of conductors on which the dampers are mounted, for optimum damping of aeolian vibration. Methods of determining power dissipated in vibrating conductors and dampers are developed. Data on such power dissipation and on power input from wind to vibrating conductors are combined to obtain estimates of vibration amplitude. The results of the estimates are checked by comparison of records of vibration of outdoor spans exposed to wind.
33 citations
TL;DR: In this paper, the authors apply the decay test to transmission line conductors to evaluate conductor self-damping on laboratory spans, using logarithmic response recorders to simplify the data reduction.
Abstract: Application of the vibration decay test to transmission line conductors provides a simple method of evaluating conductor self-damping on laboratory spans. Although special recording methods are not necessary, logarithmic response recorders simplify the data reduction. The procedure can be used to investigate the effects of stringing tension, external damping, and conductor history on conductor self-damping. The prime advantage of the decrement procedure is its simplicity and the ease of data reduction.
18 citations
TL;DR: An analysis of the vibration of cables and dampers, representing the results of several years of research and laboratory and field testing, is presented in this paper, where applications of the formulas to specific cases are given.
Abstract: An analysis of the vibration of cables and dampers, representing the results of several years of research and laboratory and Field testing, is presented in this paper. In Part I, presented herewith, an explanation of the causes and nature of free harmonic vibration of the cable is offered followd by an of the cable is offered, followed by an analysis of the resulting stresses. In Part II, which is scheduled for publication in a subsequent issue, various ways or reducing the maximum stresses and means of controlling the vibration are discussed, including an analysis of the action of Stockbridge dampers. Applications of the formulas to specific cases are given, and comparisons are made with experimental data from laboratory and field.
12 citations