Feasibility Study of Passive Electromagnetic Dampers for Vibration Control of Stay Cables

2013 ◽  
Vol 438-439 ◽  
pp. 1141-1144 ◽  
Author(s):  
Zhi Hao Wang ◽  
Guang Ping Hua
Keyword(s):  
Vibration Control ◽  
Electrical Performance ◽  
Control Technology ◽  
Test Results ◽  
Cable Vibration ◽  
Stay Cables ◽  
Controlling System ◽  
Modal Damping ◽  
Electromagnetic Damper ◽  
Cable Stayed Bridges

Effective vibration control technology for stay cables is extremely critical to safe operations of cable-stayed bridges. This paper focuses on a new cable vibration control technology and introduces an electromagnetic damper being tested for its electrical performance. Control performance of a model cable attached with a passive electromagnetic damper was investigated in the laboratory. The test results show that modal damping ratios of the cable in the first four modes can be improved significantly with the electromagnetic damper. As such, advantages and feasibilities of this new cable vibration controlling system are finally demonstrated.

Experimental Study on Multi-Mode Vibration Control of a Stay Cable with a Passive Magnetorheological Damper

2013 ◽  
Vol 361-363 ◽  
pp. 1402-1405
Author(s):  
Zhi Hao Wang
Keyword(s):  
Vibration Control ◽  
Mr Damper ◽  
Magnetorheological Damper ◽  
Test Results ◽  
Stay Cable ◽  
Mr Dampers ◽  
Stay Cables ◽  
Modal Damping ◽  
Mode Vibration ◽  
Multi Mode

Effective vibration control technology for stay cables is extremely critical to safe operations of cable-stayed bridges. For super-long cables, passive linear damper cannot provide sufficient damping since it can be only optimum for a given mode of cable, while a long cable may vibrate with several modes. This paper focuses on multi-mode vibration control of stay cables with passive magnetorheological (MR) dampers. Firstly, a 21.6m-long model cable was designed and established in the laboratory.Then, control performance of the cable with a passive MR damper was tested. The test results show that modal damping ratios of the cable in the first four modes can be improved significantly with the MR damper. It is further demonstrated that optimal tuned passively operated MR damper can outperform the passive viscous damper.

scholarly journals Serviceability Assessment Method of Stay Cables with Vibration Control Using First-Passage Probability

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Seunghoo Jeong ◽  
Young-Joo Lee ◽  
Sung-Han Sim
Keyword(s):  
Vibration Control ◽  
Control Method ◽  
Principal Component ◽  
Assessment Method ◽  
Stay Cable ◽  
First Passage ◽  
Long Span Bridges ◽  
Long Span ◽  
Stay Cables ◽  
Cable Stayed Bridges

As the construction of long-span bridges such as cable-stayed bridges increases worldwide, maintaining bridge serviceability and operability has become an important issue in civil engineering. The stay cable is a principal component of cable-stayed bridges and is generally lightly damped and intrinsically vulnerable to vibration. Excessive vibrations in stay cables can potentially cause long-term fatigue accumulation and serviceability issues. Previous studies have mainly focused on the mitigation of cable vibration within an acceptable operational level, while little attention has been paid to the quantitative assessment of serviceability enhancement provided by vibration control. This study accordingly proposed and evaluated a serviceability assessment method for stay cables equipped with vibration control. Cable serviceability failure was defined according to the range of acceptable cable responses provided in most bridge design codes. The cable serviceability failure probability was then determined by means of the first-passage problem using VanMarcke’s approximation. The proposed approach effectively allows the probability of serviceability failure to be calculated depending on the properties of any installed vibration control method. To demonstrate the proposed method, the stay cables of the Second Jindo Bridge in South Korea were evaluated and the analysis results accurately reflected cable behavior during a known wind event and show that the appropriate selection of vibration control method and properties can effectively reduce the probability of serviceability failure.

Development of Cable-Exciting System for Evaluating Modal Damping of Stay Cables

2005 ◽  
Vol 11 (4) ◽  
pp. 481-498 ◽  
Author(s):  
Nam-Sik Kim ◽  
Woon Jeong
Keyword(s):  
Dynamic Characteristics ◽  
Forced Vibration ◽  
Dynamic Properties ◽  
Equation Of Motion ◽  
Cable Model ◽  
Cable Vibration ◽  
Design Formula ◽  
Stay Cables ◽  
Modal Damping ◽  
Exciting System

One of the effective alternatives to suppress hazardous vibration of stay cables is to use cable dampers. In order to design the cable damper optimally, it is necessary to exactly estimate the dynamic characteristics of existing cables. To estimate more reliable dynamic properties of stay cables, precise excitations inducing forced vibration are needed. Hence, in this paper, a cable-exciting system (cable exciter) controlled digitally is developed. A design formula for the cable exciter is also derived by the solution of the equation of motion of a cable-exciter system. The performance of the cable exciter is verified by sine sweeping tests and resonance tests for a cable model in a laboratory. Also from those tests, more reliable dynamic properties of the cable model are obtained. Thus, it is ascertained that modal damping of stay cables is proportional to the amplitude of cable vibration.

scholarly journals Match of Negative Stiffness and Viscous Damping in a Passive Damper for Cable Vibration Control

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Peng Zhou ◽  
Qinghe Fang
Keyword(s):  
Vibration Control ◽  
Discrete Model ◽  
Negative Stiffness ◽  
Practical Significance ◽  
Viscous Damping ◽  
Stay Cable ◽  
Cable Vibration ◽  
Optimal Match ◽  
Passive Damper ◽  
Modal Damping

Match of negative stiffness and viscous damping in a passive negative stiffness damper (NSD) is studied for the vibration control of stay cables in this paper. At first, a discrete model of the stay cable with an NSD attached perpendicularly near the support is established. Under sinusoidal excitations, forced responses of the system are derived theoretically, which results in an asymptotic form for the additional modal damping ratios. Then, experimental results are presented to verify the discrete model and the corresponding theoretical derivations. Subsequently, numerical analysis is performed further to show the optimal match of negative stiffness and viscous damping, which is a function of the attachment location. The energy dissipated by the NSD and the cable energy are analyzed, thereby demonstrating the change trend of the additional modal damping ratios. Moreover, the energy distribution along the cable is investigated to reveal the effect of the negative stiffness and viscous damping. This study demonstrates the control mechanism of negative stiffness and viscous damping in the passive damper and is of practical significance for designing the optimal match of the damper parameters for cable vibration control.

Feasibility of Using a Negative Stiffness Damper to Two Interconnected Stay Cables for Damping Enhancement

2019 ◽  
Vol 19 (06) ◽  
pp. 1950058 ◽  
Author(s):  
Peng Zhou ◽  
Min Liu ◽  
Huigang Xiao ◽  
Hui Li
Keyword(s):  
Dynamic Behavior ◽  
Dynamic Responses ◽  
Negative Stiffness ◽  
Cable Stayed Bridge ◽  
Long Span ◽  
Stay Cables ◽  
Modal Damping ◽  
Vibration Responses ◽  
White Noises ◽  
Cable Stayed Bridges

The dynamic behavior of stay cables has a significant impact on the safety and serviceability of cable-stayed bridges. As tuning such dynamic behavior could be effectively achieved by a damping increase on stay cables, this paper investigates on the feasibility of increasing damping on two stay cables simultaneously through interconnecting them with a negative stiffness damper (NSD). It presents the passive realization of the NSD through the following process. First, under harmonic excitations, the steady-state dynamic responses of the two cables in the network are derived. Then, the asymptotic solutions for the additional modal damping ratios are formulated with the critical viscous damping and negative stiffness determined approximately. Subsequently, a parametric analysis is performed to verify the theoretical derivations using two stay cables of a real long-span cable-stayed bridge, under a series of numerical evaluations consisting of sinusoidal excitations and white noises vibrational responses for both cables. Both the theoretical and numerical results show superior damping enhancement by the NSD, in that the vibration responses of the two cables are reduced remarkably.

Investigation of modal damping ratios for stay cables based on stochastic subspace identification with ambient vibration measurements

2019 ◽  
Vol 22 (16) ◽  
pp. 3444-3460 ◽  
Author(s):  
Chien-Chou Chen ◽  
Wen-Hwa Wu ◽  
Szu-Ting Yu ◽  
Gwolong Lai
Keyword(s):  
Energy Dissipation ◽  
Damping Ratio ◽  
Ambient Vibration ◽  
Subspace Identification ◽  
Stochastic Subspace Identification ◽  
Modal Damping Ratio ◽  
Stay Cables ◽  
Modal Damping ◽  
Ambient Vibration Measurements ◽  
Cable Stayed Bridges

The stability assessment of stay cables based on the damping ratios of lower cable modes has attracted a large amount of research efforts. An accurate determination of those modal damping ratios is consequently required for the analysis or health monitoring of cable-stayed bridges. The aim of this study was to explore the challenge in accurately identifying the modal damping ratios of stay cable. The ambient vibration measurements collected from the stay cables of four cable-stayed bridges are investigated to cover different characteristics. A recently developed methodology based on stochastic subspace identification is adopted to determine the modal damping ratios of the cable. With the identified modal damping ratios for the stay cables of four bridges, comparison is made to examine the range of cable damping in different cable-stayed bridges and discuss the effects of several influence factors. It is found that the modal damping ratios for the stay cables of investigated bridges typically fall between 0% and 0.7%, close to the range from 0.05% to 0.5% reported by Post-Tensioning Institute. Moreover, it is also discovered that the modal damping ratio of the cable would decrease with increasing cable length if the energy dissipation mechanism of the cable principally comes from the anchorage device. In the cases where the middle free length section of the cable is filled with effective grouting materials, the modal damping ratio of the cable is not necessarily correlated with the cable length. Finally, the obtained results also indicate that the grouting material filled in the middle free length section of the cable defines the primary contribution to energy dissipation ranked by a descending order of ceresine wax, flexible polymer-modified cement and polyurethane foam.

Modeling and Evaluation of Magnetorheological Dampers with Fluid Leakage for Cable Vibration Control

2021 ◽  
Vol 26 (2) ◽  
pp. 04020119
Author(s):  
Peng Zhou ◽  
Min Liu ◽  
Weiming Kong ◽  
Yingmei Xu ◽  
Hui Li
Keyword(s):  
Vibration Control ◽  
Magnetorheological Dampers ◽  
Cable Vibration ◽  
Fluid Leakage
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