CURVED-IN-PLANE CABLE-STAYED BRIDGES: A MATHEMATICAL MODEL

2012 ◽  
Vol 12 (03) ◽  
pp. 1250011 ◽  
Author(s):  
IOANNIS G. RAFTOYIANNIS ◽  
GEORGE T. MICHALTSOS
Keyword(s):  
Mathematical Model ◽  
Three Dimensional ◽  
3D Analysis ◽  
Continuum Approach ◽  
Theoretical Formulation ◽  
Long Span ◽  
Dynamic Analyses ◽  
Tensile Forces ◽  
External Loads ◽  
Cable Stayed Bridges

A mathematical model suitable for static and dynamic analyses of curved-in-plane cable-stayed bridges is proposed. By expressing the tensile forces of the cables in relation to the deck and pylon deformations, the problem is reduced to the solution of a beam curved-in-plane that is subjected to the usual permanent and external loads and to the tensile forces of the cables, the latter being functions of the deformation of the beam. The theoretical formulation presented is based on a continuum approach, which is suitable for the three-dimensional (3D) analysis of long span cable-supported bridges. Numerical examples will be analyzed to illustrate the applicability of the proposed approach.

Improved finite strip method for nonlinear analysis of long-span cable-stayed bridges

1990 ◽  
Vol 17 (1) ◽  
pp. 87-93 ◽  
Author(s):  
M. S. Cheung ◽  
Wenchang Li ◽  
L. G. Jaeger
Keyword(s):  
Three Dimensional ◽  
Structural Response ◽  
Finite Strip ◽  
Strip Method ◽  
Cable Stayed Bridge ◽  
Long Span ◽  
Finite Strip Method ◽  
Nonlinear Solutions ◽  
Raphson Iteration ◽  
Cable Stayed Bridges

As the spans of cable-stayed bridges increase, the degree of nonlinearity of structural response increases markedly. For future spans greater than (say) 800 m, existing three-dimensional software then becomes very time consuming and costly, and a finite strip approach becomes more attractive and preferable. An improved finite strip method using two types of longitudinal shape functions is developed in this paper for the analysis of girders of such bridges. The nonlinearities due to sag and angle change of the cables are taken into account by means of catenary theory. The substructuring technique and the modified Newton–Raphson iteration method are used for nonlinear solutions. A number of numerical examples are given to show the accuracy and efficiency of this method. Key words: finite strip, continuous structure, cable-stayed bridge, substructuring, catenary, nonlinearity, iteration.

Study on the Indiscrete Tuned Mass Damper for Buffeting Control of Long Span Cable-Stayed Bridges

2012 ◽  
Vol 160 ◽  
pp. 405-409
Author(s):  
Xiong Jiang Wang ◽  
Jia Yun Xu ◽  
Ji Chen
Keyword(s):  
Three Dimensional ◽  
Element Model ◽  
Tuned Mass Damper ◽  
Buffeting Response ◽  
Long Span ◽  
Mass Damper ◽  
Dimensional Finite Element ◽  
Centre Region ◽  
Three Dimensional Finite Element ◽  
Cable Stayed Bridges

A study of buffeting control of the E-dong Bridge Using an indiscrete tuned mass damper (ITMD) system is performed in this paper. Different from the traditional multiple tuned mass damper (MTMD) system which is fixed along the main span of bridge discretely, this indiscrete tuned mass damper is attached to the centre region of the bridge’s main span continuously. A three-dimensional finite element model of E-dong Bridge, is completed by the software of ANSYS. By comparing the vertical and lateral buffeting response of bridge without dampers, the control efficiency of ITMD and MTMD is confirmed.

Effect of Shear Lag on the Long-Term Performance of Long-Span PC Box Girder Bridge

2011 ◽  
Vol 255-260 ◽  
pp. 1290-1294 ◽  
Author(s):  
Yan Wei Niu
Keyword(s):  
Prestressed Concrete ◽  
Three Dimensional ◽  
3D Analysis ◽  
Shear Lag ◽  
Box Girder Bridges ◽  
Box Girder ◽  
Girder Bridges ◽  
Long Span ◽  
Girder Bridge

The analysis and mechanism of excessive long-term deflection of long-span prestressed concrete (PC) box girder bridges is concentrated recently. However, because of the lack of computing method, three dimensional (3D) analysis of PC continuous bridge especially including long-term shear lag effect is hard to analyze. According to this, a 3D creep analysis method for long-span PC bridges is illustrated in this paper first. The shear lag analysis of loads, prestress and their combination effect is carried out respectively. Based on this, the effect of shear lag to the long-term deflection of mid-span and whole-shape of the bridge is demonstrated. At the end, the different of computing between analysis with or without considering shear lag is discussed and some suggestion is proposed.

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.

A Real-Time Mathematical Model for Three-Dimensional Tidal Flow and Water Quality

1991 ◽  
Vol 24 (6) ◽  
pp. 171-177 ◽  
Author(s):  
Zeng Fantang ◽  
Xu Zhencheng ◽  
Chen Xiancheng
Keyword(s):  
Mathematical Model ◽  
Water Quality ◽  
Real Time ◽  
Control Volume ◽  
Tidal Flow ◽  
Three Dimensional ◽  
River Estuary ◽  
Pearl River Estuary ◽  
Practical Application ◽  
The Pearl River

A real-time mathematical model for three-dimensional tidal flow and water quality is presented in this paper. A control-volume-based difference method and a “power interpolation distribution” advocated by Patankar (1984) have been employed, and a concept of “separating the top-layer water” has been developed to solve the movable boundary problem. The model is unconditionally stable and convergent. Practical application of the model is illustrated by an example for the Pearl River Estuary.

scholarly journals Three-dimensional assessment of the anterior and inferior loop of the inferior alveolar nerve using computed tomography images in patients with and without mandibular asymmetry

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jae-Young Kim ◽  
Michael D. Han ◽  
Kug Jin Jeon ◽  
Jong-Ki Huh ◽  
Kwang-Ho Park
Keyword(s):  
Computed Tomography ◽  
Symmetry Group ◽  
Three Dimensional ◽  
Inferior Alveolar Nerve ◽  
Mental Foramen ◽  
3D Analysis ◽  
Mandibular Asymmetry ◽  
Computed Tomography Images ◽  
Significant Difference ◽  
Mandibular Body

Abstract Background The purpose of this study was to investigate the differences in configuration and dimensions of the anterior loop of the inferior alveolar nerve (ALIAN) in patients with and without mandibular asymmetry. Method Preoperative computed tomography images of patients who had undergone orthognathic surgery from January 2016 to December 2018 at a single institution were analyzed. Subjects were classified into two groups as “Asymmetry group” and “Symmetry group”. The distance from the most anterior and most inferior points of the ALIAN (IANant and IANinf) to the vertical and horizontal reference planes were measured (dAnt and dInf). The distance from IANant and IANinf to the mental foramen were also calculated (dAnt_MF and dInf_MF). The length of the mandibular body and symphysis area were measured. All measurements were analyzed using 3D analysis software. Results There were 57 total eligible subjects. In the Asymmetry group, dAnt and dAnt_MF on the non-deviated side were significantly longer than the deviated side (p < 0.001). dInf_MF on the non-deviated side was also significantly longer than the deviated side (p = 0.001). Mandibular body length was significantly longer on the non-deviated side (p < 0.001). There was no significant difference in length in the symphysis area (p = 0.623). In the Symmetry group, there was no difference between the left and right sides for all variables. Conclusion In asymmetric patients, there is a difference tendency in the ALIAN between the deviated and non-deviated sides. In patients with mandibular asymmetry, this should be considered during surgery in the anterior mandible.

Research on cargo-loading optimization based on genetic and fuzzy integration

2021 ◽  
Vol 40 (4) ◽  
pp. 8493-8500
Author(s):  
Yanwei Du ◽  
Feng Chen ◽  
Xiaoyi Fan ◽  
Lei Zhang ◽  
Henggang Liang
Keyword(s):  
Genetic Algorithm ◽  
Mathematical Model ◽  
Three Dimensional ◽  
Distribution Center ◽  
Long Time ◽  
Low Efficiency ◽  
Decision Making Model ◽  
The Mathematical Model ◽  
Loading Scheme

With the increase of the number of loaded goods, the number of optional loading schemes will increase exponentially. It is a long time and low efficiency to determine the loading scheme with experience. Genetic algorithm is a search heuristic algorithm used to solve optimization in the field of computer science artificial intelligence. Genetic algorithm can effectively select the optimal loading scheme but unable to utilize weight and volume capacity of cargo and truck. In this paper, we propose hybrid Genetic and fuzzy logic based cargo-loading decision making model that focus on achieving maximum profit with maximum utilization of weight and volume capacity of cargo and truck. In this paper, first of all, the components of the problem of goods stowage in the distribution center are analyzed systematically, which lays the foundation for the reasonable classification of the problem of goods stowage and the establishment of the mathematical model of the problem of goods stowage. Secondly, the paper abstracts and defines the problem of goods loading in distribution center, establishes the mathematical model for the optimization of single car three-dimensional goods loading, and designs the genetic algorithm for solving the model. Finally, Matlab is used to solve the optimization model of cargo loading, and the good performance of the algorithm is verified by an example. From the performance evaluation analysis, proposed the hybrid system achieve better outcomes than the standard SA model, GA method, and TS strategy.

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