Optimal Design of Damper with Stiffness for Damping of Stay Cable under Bridge Deck Motion

2013 ◽  
Vol 438-439 ◽  
pp. 769-774
Author(s):  
Shuai Luo ◽  
Quan Sheng Yan ◽  
Hong Jun Liu
Keyword(s):  
Optimal Design ◽  
Bridge Deck ◽  
Damping Coefficient ◽  
Viscous Damper ◽  
Stay Cable ◽  
Rule Of Thumb ◽  
Modal Damping ◽  
Inclined Angle

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.

Design of Mitigation Damper with Support Flexibility for Stay Cable under Bridge Deck Excitation

2012 ◽  
Vol 238 ◽  
pp. 714-718
Author(s):  
Shuai Luo ◽  
Quan Sheng Yan ◽  
Hong Jun Liu
Keyword(s):  
Bridge Deck ◽  
Damping Coefficient ◽  
Viscous Damper ◽  
Stay Cable ◽  
Rule Of Thumb ◽  
Modal Damping ◽  
Inclined Angle

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.

Damping of Stay Cable-Passive Damper System with Effects of Cable Bending Stiffness and Damper Stiffness

2012 ◽  
Vol 204-208 ◽  
pp. 4513-4517 ◽  
Author(s):  
Min Liu ◽  
Guang Qiao Zhang
Keyword(s):  
Numerical Analysis ◽  
Damping Ratio ◽  
Bending Stiffness ◽  
Damping Coefficient ◽  
Stay Cable ◽  
Modal Damping Ratio ◽  
Passive Damper ◽  
Modal Damping ◽  
Optimal Damping ◽  
Coefficient Increase

In the present paper, the asymptotic solution of modal damping ratio of stay cable-passive damper system with the influence of cable bending stiffness and damper stiffness was derived. Maximum modal damping ratio and corresponding optimal damping coefficient, which indicated the relationships of the characteristics of the damper and the cable bending stiffness was theoretically analyzed to obtain their close solutions. On the basis of these close solutions, numerical analysis of modal damping of stay cable-passive damper system with the effects of cable bending stiffness and damper stiffness was conducted. The numerical and analytical results show that the maximum modal damping ratio decrease and the corresponding damping coefficient increase, when considering the influence of the damper stiffness and the cable bending stiffness.

Research on the Modal Damping Ratio for Stay Cable with Viscoselasticity Damper in Cable-Stayed Bridges

2013 ◽  
Vol 779-780 ◽  
pp. 671-674
Author(s):  
Shui Sheng Chen ◽  
De Shan Wang
Keyword(s):  
Damping Ratio ◽  
Bending Stiffness ◽  
Complex Eigenvalue ◽  
Stay Cable ◽  
Modal Damping Ratio ◽  
Modal Damping ◽  
Out Of Plane ◽  
Damper Design ◽  
Inclined Angle ◽  
Separation Strategy

Taking the bending stiffness, cable static sag and cable inclined angle into consideration, equations of space free vibration of the cable-damper system are derived in this paper. Joining the variable separation strategy and center difference method, the partial differential equations are discretized in space and a set of complex eigenvalue equations, which are solved by state space method, are derived, and both the maximum modal damping ration and the optimal damper parameter are obtained. Several typical stay cables are investigated for both the in-plane and out-of-plane modes under different cable parameters and damper parameters. The results demonstrate that modal damping ratio for the first in-plane mode is significantly affected by the cable static sag only, but those for the other modes affected by cable sag are slight, and cable static sag do not affect the optimal damper parameter for all modes, however the bending stiffness will changes both the maximum modal damping ratios and the optimal damper parameters. Some valuable suggestions are proposed for the optimal damper design.

scholarly journals Inertial mass damper for vibration control of cable with sag

2018 ◽  
Vol 39 (3) ◽  
pp. 749-760 ◽  
Author(s):  
Zhi-Hao Wang ◽  
Hui Gao ◽  
Bu-qiao Fan ◽  
Zheng-Qing Chen
Keyword(s):  
Inertial Mass ◽  
Damping Coefficient ◽  
Stay Cables ◽  
Modal Damping ◽  
Optimal Damping ◽  
Mass Damper ◽  
Negative Effect ◽  
Supplemental Damping ◽  
Antisymmetric Vibrations ◽  
General Dynamic

It has been theoretically predicted that superior supplemental damping can be generated for a taut cable with an inertial mass damper. This paper extends previous studies to investigate the effect of the cable sag on the efficiency of an inertial mass damper. The general dynamic characteristics of an inclined sag cable with an inertial mass damper installed close to the cable end are theoretically investigated. The parametric analysis of the inertial mass and the damping coefficient of the inertial mass damper are conducted to evaluate the control performance of the cable with different sags. The results show that the inertial mass damper can alleviate the negative effect induced by the cable sag, and the cable sag can even increase modal damping ratios provided by the inertial mass damper. Sags of stay cables used in actual bridges only affect nearly symmetric vibrations of cables, while having little impact on nearly antisymmetric vibrations. The effect of cable sags will reduce the optimal damping coefficient and inertial mass of the inertial mass damper for the first symmetric mode of the cable.

scholarly journals Tailoring of Composite Links for Optimal Damped Elasto-Dynamic Performance

1989 ◽  
Author(s):  
D. A. Saravanos ◽  
C. C. Chamis
Keyword(s):  
Optimal Design ◽  
Dynamic Stiffness ◽  
Dynamic Performance ◽  
Performance Criteria ◽  
Modal Damping ◽  
Trade Offs ◽  
Design Variables ◽  
Material Systems ◽  
Structural Composite ◽  
Selective Minimization

Abstract A method is developed for the optimal design of composite links based on dynamic performance criteria directly related to structural modal damping and dynamic stiffness. An integrated mechanics theory correlates structural composite damping to the parameters of basic composite material systems, laminate parameters, link shape, and modal deformations. The inclusion of modal properties allows the selective minimization of vibrations associated with specific modes. Ply angles and fiber volumes are tailored to obtain optimal combinations of damping and stiffness. Applications to simple composite links indicate wide margins for trade-offs and illustrate the importance of various design variables to the optimal design.

scholarly journals Modal Damping Coefficient Estimation of Carbon-Fiber-Reinforced Plastic Material Considering Temperature Condition

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2872 ◽  
Author(s):  
Ho-Young Kang ◽  
Chan-Jung Kim ◽  
Jaewoong Lee
Keyword(s):  
Carbon Fiber ◽  
Frequency Response ◽  
Plastic Material ◽  
Damping Coefficient ◽  
Carbon Fiber Reinforced Plastic ◽  
Fiber Reinforced ◽  
Fiber Reinforced Plastic ◽  
Modal Damping ◽  
Reinforced Plastic ◽  
Carbon Fiber Reinforced

Excellent mechanical properties of carbon-fiber-reinforced plastic material (CFRP) demonstrates many possibilities in industries using lightweight materials, but unlike isotropic materials, such as iron, aluminum, and magnesium, they show direction-sensitive properties, which makes it difficult to apply for them. The sensitivity of a modal damping coefficient of a CFRP material over the direction of carbon fiber was examined on spectral input patterns in recent research, but the effect of temperature was not considered up to now. To overcome this, uniaxial vibration tests were conducted using five simple specimens with different direction of carbon fiber in a CFRP specimen, the frequency response functions were experimentally determined and the modal damping coefficients were calculated. It was revealed that the resonance point and the modal damping of the specimen changed according to the change in temperature condition. Based on the experimental results, it was demonstrated that the theoretical frequency response function of the carbon composite material is a function of temperature, and it was confirmed that the nonlinear characteristic of the modal damping was the smallest under the 0 degree of direction of carbon fiber.

Study on Dynamics Characteristics of SINS Damping System in Shock Environment

2013 ◽  
Vol 397-400 ◽  
pp. 355-358
Author(s):  
Xia Qing Tang ◽  
Jun Qiang Gao ◽  
Li Bin Guo ◽  
Huan Zhang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Optimal Design ◽  
Vibration Isolation ◽  
Damping Coefficient ◽  
Shock Environment ◽  
Stiffness And Damping Coefficient ◽  
Stiffness And Damping ◽  
Element Method

Dynamics characteristics of SINS damping system in shock environment were analyzed by finite element method, as the deformation of dampers may leads to the accuracy loss of SINS. In addition, the influence of absorber stiffness and damping coefficient on dynamics characteristics were studied. The results indicate that the decoupling of vibrations is significant for the accuracy of SINS. However, considering the almost impossible of completely decoupled vibrations, its necessary to carry out an optimal design of the absorber stiffness and damping coefficient to maintain the accuracy of SINS while meeting the requirement of vibration isolation.

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 Modal Interaction-Induced Parametric Resonance of Stayed Cable: A Combined Theoretical and Experimental Investigation

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Qi-Chang Zhang ◽  
Su-Yu Cui ◽  
Zhi Fu ◽  
Jian-Xin Han
Keyword(s):  
Natural Frequency ◽  
Parametric Resonance ◽  
Bridge Deck ◽  
Primary Resonance ◽  
Second Order ◽  
Stay Cable ◽  
Modal Interaction ◽  
External Excitation ◽  
First Order ◽  
Principal Parametric Resonance

The cable-stayed bridge is widely used due to its strong spanning capacity and navigability. However, flexible cables parametrically resonated by external excitation may result in instability or even damage to the bridge. To prevent such undesirable resonance, this paper discusses an in-plane modal interaction-induced parametric resonance of the stayed cable excited by the bridge deck vibration via nonlinear dynamic analysis. Based on the nonlinear distributed model, two modal governing equations of the cable are established via the Galerkin method. A certain working condition, when the external excitation frequency is close to the second-order natural frequency of the stay cable while nearly twice the first-order natural frequency, is theoretically and experimentally investigated. Specifically, the frequency response equations are obtained by the multiscale method, and the stability of solutions is examined through the Routh Hurwitz criterion. Theoretical and experimental results show that bridge deck vibration can induce not only the primary and superharmonic resonance of the cable but also the principal parametric resonance. Parametric resonance-induced bifurcations are also observed in the system. Particularly, the energy exchange from second-order primary resonance to first-order principal parametric resonance is found, which can induce the parametric resonance with the response amplitude one to three times higher than that of the primary resonance. This paper also validates the superiority of the present modal interaction model over the traditional single-mode model in practical engineering applications.

Dynamic Performance Optimization of Cylindrical Shell with Constrained Damping Layer Using Topology

2012 ◽  
Vol 479-481 ◽  
pp. 1209-1215
Author(s):  
Ming Xu Wang ◽  
Qi Zhi Li
Keyword(s):  
Cylindrical Shell ◽  
Performance Optimization ◽  
Dynamic Performance ◽  
Target Function ◽  
Damping Coefficient ◽  
Topological Optimization ◽  
Constraint Function ◽  
Modal Damping ◽  
Constrained Damping ◽  
Damping Materials

Topology optimization of the constrained damping cylindrical shell for the maximized modal damping coefficient is studied in this paper. According to the first 3 orders modes, a novel topological optimization model where the volume is taken as the constraint function and the function of the modal damping coefficient as the target function is proposed and analyzed. The reasonable topology configuration was obtained for the damping structure. The results show that this method can be applied to solve the problem of optimization of the constrained damping cylindrical shell with the damping materials volume constrained. Numerical simulations are performed to very the effectiveness of the presented method.

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