Role of dynamic water rivulets in the excitation of rain–wind-induced cable vibration: A critical review

2021 ◽  
pp. 136943322110401
Author(s):  
Donglai Gao ◽  
Wenjie Li ◽  
Haiquan Jing ◽  
Jian Wang ◽  
Jintuan Wu ◽  
...  
Keyword(s):  
Wind Engineering ◽  
Excitation Mechanism ◽  
Structure Interaction ◽  
Wall Boundary Layer ◽  
Stay Cables ◽  
Considerable Research ◽  
Complex Fluid ◽  
Wind Induced Vibration ◽  
Cable Stayed Bridges

It has been more than 30 years since Hikami Y and Shiraishi N (1988) Rain–wind-induced vibrations of cable-stayed bridges. Journal of Wind Engineering and Industrial Aerodynamics 29: 409–418 first reported the rain–wind-induced vibration (RWIV) of stay cables in the construction stage of Meikonishi Bridge, Japan. After that, considerable research efforts have been devoted to understanding the RWIV of stay cables, and the role of the upper rivulet has been gradually realized and studied. This study presents a selective review on recent progress of RWIV and its controversial excitation mechanism. The available knowledge and up-to-date understanding of this complex fluid-structure interaction are presented in some detail. The formation, dynamics of water rivulet, and its role in affecting the near-wall boundary layer properties and in the excitation scenario of RWIV are of particular interest in this study. Finally, some limitations of previous studies are concluded, with some perspective suggestions for further study of excitation mechanism of RWIV.

scholarly journals A 2D model for analysis of rain-wind induced vibration of stay cables

2019 ◽  
Vol 13 (2) ◽  
pp. 33-47
Author(s):  
Truong Viet Hung ◽  
Vu Quang Viet
Keyword(s):  
Harmonic Oscillation ◽  
Impact Angle ◽  
Angular Frequency ◽  
Initial Position ◽  
Initial Angle ◽  
Aerodynamic Forces ◽  
Stay Cables ◽  
Wind Induced Vibration ◽  
The Impact ◽  
Cable Stayed Bridges

Rain-wind induced vibration of stay cables (RWIV) in cable-stayed bridges is a special aerodynamic phenomenon as it is easy to be influenced by many factors, especially velocity and impact angle of wind. This paper proposes a new assumption of the impact angle of wind on the cable in analyzing cable vibration response subjected to wind and rain. This angle is considered as a harmonic oscillation function around the equilibrium position that is the initial angle of impact, and its angular frequency equals of the rivulet and the cable. The amplitude of impact angle of wind depends on wind velocity, initial position and that of rivulet. The assumption is verified by comparison with experimental results. The effects of rivulet oscillation components and aerodynamic forces are also discussed in this paper. Keywords: cable; rain-wind induced vibration; rivulet; analytical model; vibration.

The Role of Axial Flow in Near Wake on the Cross-Flow Vibration of the Inclined Cable of Cable-Stayed Bridges

2010 ◽  
Author(s):  
Masaru Matsumoto
Keyword(s):  
Vortex Shedding ◽  
Cross Flow ◽  
Axial Flow ◽  
Splitter Plate ◽  
Near Wake ◽  
Karman Vortex ◽  
The Cross ◽  
Wind Induced Vibration ◽  
Cable Stayed Bridges

Nowadays, the violent wind-induced vibration, including “rain-wind induced vibration” and “dry-galloping”, of stay-cables of cable-stayed bridges has become the most serious issue for bridge design. Up-to-date, the major factors for excitation of inclined cables have been clarified to be, for “rain-wind” induced vibration, the formation of “water-rivulet” on the particular position of upper cable surface, and, for “dry galloping”, the “axial flow” which flows in the near wake along cable-axis, and the effect of drag-force associated with Reynolds number, separately. However, the details of the effect of “axial flow” remain unsolved. Thus, this study aims to clarify the effect of axial flow in near wake on the aero-elastic vibration of inclined cables basing on various experiments. The mean velocity of axial flow was almost 60% of approaching wind velocity. Furthermore, the aerodynamic effect of the “axial flow” on cross-flow vibration of inclined cables is discussed in relation to the mitigation of Karman vortex shedding in near wake. Since the role of axial flow seems to be similar to the splitter plate installed in wake from the point of mitigation of Karman vortex shedding, to clarify the cross-flow response in relation to the mitigation of Karman vortex, the perforated ratio of the splitter plate was variously changed, then the similarity of effect of axial flow and the one of splitter plate was verified comparing their unsteady lift force-characteristics. In summary, it is shown that the axial flow on aerodynamic cross-flow vibration might excite like galloping similarly with the splitter plate by mitigation of Karman vortex.

Structural Design of Experimental Study on Rain-Wind-Induced Vibration of Strayed Cables

2012 ◽  
Vol 532-533 ◽  
pp. 412-416
Author(s):  
Wei Li ◽  
Wei Guo ◽  
Hua Bai
Keyword(s):  
Aerodynamic Characteristics ◽  
Wind Pressure ◽  
3 Dimensional ◽  
Pressure Coefficients ◽  
Long Span ◽  
Stay Cables ◽  
Safe Production ◽  
Wind Induced Vibration ◽  
Fluctuating Wind ◽  
Cable Stayed Bridges

To study the aerodynamic characteristics of strayed cable under wind and rain, with the object of the Zhijiang bridge, pressure experiments on the 2- and 3-dimensional models of stay cables in wind tunnel are made. Mean and fluctuating wind-pressure coefficients with 2 kinds of surface morphology under different wind direction angle are obtained. The results show that the rivulet position will greatly influence the distribution of pressure coefficients on the cable surface, and the separation point of the flow nearby the rivulet will be changed obviously. Aerodynamic coefficients will be changed when the rivulet be in a certain position, then the rain-wind-induced vibration will occur .The experimental results will be the guidance for the wind-resistant design and the safe production of the long-span cable-stayed bridges.

Response characteristics of rain-wind induced vibration of stay-cables of cable-stayed bridges

1995 ◽  
Vol 57 (2-3) ◽  
pp. 323-333 ◽  
Author(s):  
Masaru Matsumoto ◽  
Tohru Saitoh ◽  
Masahiko Kitazawa ◽  
Hiromichi Shirato ◽  
Takayuki Nishizaki
Keyword(s):  
Response Characteristics ◽  
Stay Cables ◽  
Wind Induced Vibration ◽  
Cable Stayed Bridges

scholarly journals A three-dimensional model for rain-wind induced vibration of stay cables in cable-stayed bridges

2019 ◽  
Vol 14 (1) ◽  
pp. 89-102
Author(s):  
Truong Viet Hung ◽  
Vu Quang Viet ◽  
Vu Quoc Anh
Keyword(s):  
Wind Velocity ◽  
Three Dimensional ◽  
Stay Cable ◽  
Three Dimensional Model ◽  
Central Difference ◽  
Theoretical Formulation ◽  
Wind Speed Profile ◽  
Stay Cables ◽  
Wind Induced Vibration ◽  
Cable Stayed Bridges

In this paper, the effects of wind velocity according to height above the ground on the rain-wind induced vibration (RWIV) of stay cables are investigated. RWIV of the cable is modeled using the linear theory of cable vibration and the central difference algorithm. The wind speed profile according to height above the ground, which affects both aerodynamic forces acting on the cable and the oscillation of the rivulet on the cable surface, is taken into account in the theoretical formulation. The fourth-order method Runge-Kutta is used for solving the system of differential equation of the cable oscillation. The proposed 3D model of the stay cable is then used to assess the effects of wind velocity distribution on cable RWIV. The results obtained in this study showed that in most current cable-stayed bridges, in which the height of pylons is lower than 200 m, the change of wind velocity according to the height above the ground should be included in RWIV analyses. Keywords: stay cable; rain - wind induced vibration; rivulet; analytical model; vibration.

scholarly journals A Monolithic Approach of Fluid–Structure Interaction by Discrete Mechanics

Fluids ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 95
Author(s):  
Stéphane Vincent ◽  
Jean-Paul Caltagirone
Keyword(s):  
Solid Mechanics ◽  
Mechanical Energy ◽  
Fluid Structure Interaction ◽  
Equation Of Motion ◽  
Discrete Equation ◽  
Discrete Mechanics ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Vector Potentials

The unification of the laws of fluid and solid mechanics is achieved on the basis of the concepts of discrete mechanics and the principles of equivalence and relativity, but also the Helmholtz–Hodge decomposition where a vector is written as the sum of divergence-free and curl-free components. The derived equation of motion translates the conservation of acceleration over a segment, that of the intrinsic acceleration of the material medium and the sum of the accelerations applied to it. The scalar and vector potentials of the acceleration, which are the compression and shear energies, give the discrete equation of motion the role of conservation law for total mechanical energy. Velocity and displacement are obtained using an incremental time process from acceleration. After a description of the main stages of the derivation of the equation of motion, unique for the fluid and the solid, the cases of couplings in simple shear and uniaxial compression of two media, fluid and solid, make it possible to show the role of discrete operators and to find the theoretical results. The application of the formulation is then extended to a classical validation case in fluid–structure interaction.

scholarly journals Numerical Modeling of Sperm Swimming

Fluids ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 73
Author(s):  
Fang-Bao Tian ◽  
Li Wang
Keyword(s):  
Sperm Quality ◽  
Computational Studies ◽  
Theoretical Methods ◽  
Structure Interaction ◽  
Sperm Density ◽  
Fluid Environment ◽  
Complex Fluid ◽  
Fluid Rheology ◽  
Wall Interactions ◽  
Open Issues

Due to rising human infertility, sperm motility has been an important subject. Among the hundreds of millions of sperms on the journey up the oviducts, only a few excellent travelers will reach the eggs. This journey is affected by many factors, some of which include sperm quality, sperm density, fluid rheology and chemotaxis. In addition, the sperm swimming through different body tracks and fluids involves complex sperm flagellar, complex fluid environment, and multi-sperm and sperm-wall interactions. Therefore, this topic has generated substantial research interest. In this paper, we present a review of computational studies on sperm swimming from an engineering perspective with focus on both simplified theoretical methods and fluid–structure interaction methods. Several open issues in this field are highlighted.

Early Adverse Childhood Experiences and Self-Control Development among Youth in Fragile Families

2021 ◽  
pp. 0044118X2199637
Author(s):  
Melissa S. Jones ◽  
Hayley Pierce ◽  
Constance L. Chapple
Keyword(s):  
Life Course ◽  
Adverse Childhood Experiences ◽  
Behavioral Outcomes ◽  
Self Control ◽  
Fragile Families ◽  
Childhood Experiences ◽  
Considerable Research ◽  
Adverse Childhood ◽  
Using Data

Though considerable research links both a lack of self-control and adverse childhood experiences (ACEs) to a variety of negative health and behavioral outcomes, few studies to date have explored whether ACEs are associated with deficits in self-control. Using data from the Fragile Families and Child Wellbeing Study (FFCW; n = 3,444) and a life course theoretical framework, this study aims to address this gap in the literature by examining the relationships between individual ACEs, cumulative ACEs, timing of ACEs, and durations of early ACEs and self-control development among youth. Our results indicate that as the number of ACEs (by age 5) experienced incrementally increases, the likelihood of reported self-control decreases. Moreover, when it comes to the timing and duration of ACE exposure, ACEs that are high but late, intermittent, or chronically high significantly decrease self-control. Based on our findings, researchers should continue to explore the role of ACEs in youth self-control development.

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