Papers by Keyword: Stay Cable

Abstract: In order to solve the problem of bending stiffness parameters identification of practical stay-cable, and provide bending stiffness correction for tension measurement. A method to identify cable bending stiffness parameters is proposed, and its basis theory established in paper. The method was applied to Xiazhang Sea-Crossing Bridge, the results showed that: Identification bending stiffness ratio is between 0.33 to 0.54 for relatively short cables of South Branch Bridge, and it tends to decrease with increase of cable length and force. However, the identification bending stiffness is close or equal to 0 EI_max for relatively long cable of North Branch Bridge. It testified that the effect of bending stiffness for long cable tension is small in engineering.

Abstract: The construction of stay cable is the key technology problem in large span spatial structures. This paper carried out a study on the construction scheme of stay cables based on the practical project of Shiyan stadium roof. The loss of tensile force caused by the seven steel wring with different construction order is summarized according to the experimental construction, and the tensile force slacken analysis method was used to calculate the stress of construction. Moreover, the loss of tensile force caused by anchor and relaxation is considered too. Then, the control tensile force of construction, which is used to realize the tensile construction one time, is obtained. Results of the engineering test show that the construction process is simplified and he construction scheme is economic under the condition of allowed precision. The method can provide reference for similar projects.

Abstract: An improved fuzzy semi-active control method forparametric vibration of the cable-stayed with MR damper was proposed. The parametervibration control of the cable M22 and the cable M13 of the Hongshuihecable-stayed Bridge was studied. The results show that the effect of theimproved fuzzy semi-active control strategy was better than that of the fuzzysemi-active control strategy. In addition, the proposed fuzzy semi-activecontrol strategy does not need to debug the scaling factor of input variablesand output variables and the MR damper required lower voltages. Therefore，theproposed method makes the fuzzy control more intelligent.

Abstract: The commonly used viscous dampers for cable’s vibration mitigation have some unfavorable factors, such as the damping effect is not obvious for super long stay cable, the limitation of installation position, coupling vibration, etc. The cable-tuned mass damper system vibration model is put forward to solve this problem. The optimal cable-tuned mass damper system modal damping ratio and optimum design parameters, including cable vibration order, TMD’s stiffness, TMD’s mass, and TMD’s damping, were obtained by the method of complex models. The results can provide important reference for the design of TMD for stay cable.

Abstract: 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.

Abstract: This paper studies cable-damper mitigation model due to indirect excitation caused by bridge deck vibration. In the new mitigation model, as a rule of thumb, we considered a parallel association of idealize damper with a spring to simulate the inherent stiffness of the damper. The result shows that the interaction between the stiffness of the viscous damper could deeply impact the damper effectiveness, and the external damping should be increased deeply to provide the same non-dimensional modal damping when the inclined angle of cable decreases. The optimum damping coefficient of the non-idealized damper decreases when the stiffness of the damper increases.

Abstract: 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.

Abstract: The stay cables in civil engineering are one of the most difficult components to maintain for the safety of bridge after it is open for traffic, as the slenderness ratio is large, and they are flexible, low in damping ratio and less resistant to bending. It is possible that the cable snaps under large cyclic flexural stress due to wind-induced motion, regular traffic or even ambient vibration. The loosening seal of stay cables, damaged anchors, and tendon corrosion due to damaged protection sleeve at the root will undermine dramatically the life of cable-stayed bridge and even its safety. In this paper, the field test used to determine dynamic responses for stayed cable of the bridge in civil engineering. The practice formula is used to determine the cable forces of the Kao Ping Hsi cable-stayed bridge (the largest cable-stayed bridge in Taiwan). The results obtained herein indicate that such analysis is valid and rational, and may be used to monitor the safety of cable-stayed bridge.

Abstract: Rain-wind induced vibration (RWIV) is a large amplitude and low frequency vibration of stay cables under wind and rain. The formation and oscillation of rivulets on stay cable surface plays an important role in RWIV, and it is also the symbolic characteristics of RWIV. In this paper, a numerical simulation approach of the formation process of rivulets around stay cable is presented by combining gas-liquid two-phase theory and volume of fluid method (VOF method) for the first time. The effect of gravity and air flow on morphology of rivulets is analysed by numerical simulation using computational fluid dynamics (CFD) software-CFX. The veracity and rationality of this approach is verifed by comparing with existing experimental data.

Abstract: This paper studies cable-damper mitigation model due to indirect excitation caused by bridge deck excitation. In the new mitigation model, as a rule of thumb, we considered an attached spring associated in tandem with a damper to simulate the supporter flexibility. The result shows that the interaction between the flexibility of the support in the viscous damper could deeply impact the damper effectiveness, and the external damping should be increased deeply to provide the same non-dimensional modal damping when the inclined angle of cable decreases. The optimum damping coefficient of the non-idealized damper increases when the flexibility of the supporter increases.