Initial Shape Analysis of Cable-Stayed Suspension Bridge

2012 ◽  
Vol 18 (1) ◽  
pp. 2123-2126
Author(s):  
Dong-Ho Choi ◽  
Ho-Sung Na ◽  
Sun Gil Gwon
Keyword(s):  
Shape Analysis ◽  
Suspension Bridge ◽  
Initial Shape ◽  
Initial Shape Analysis

scholarly journals Simplified Analytical Method for Optimized Initial Shape Analysis of Self-Anchored Suspension Bridges and Its Verification

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Myung-Rag Jung ◽  
Dong-Ju Min ◽  
Moon-Young Kim
Keyword(s):  
Analytical Method ◽  
Bending Moment ◽  
Suspension Bridge ◽  
Suspension Bridges ◽  
Equilibrium Equations ◽  
Initial State ◽  
Initial Shape ◽  
Main Cable ◽  
Initial Shape Analysis ◽  
Bridge Models

A simplified analytical method providing accurate unstrained lengths of all structural elements is proposed to find the optimized initial state of self-anchored suspension bridges under dead loads. For this, equilibrium equations of the main girder and the main cable system are derived and solved by evaluating the self-weights of cable members using unstrained cable lengths and iteratively updating both the horizontal tension component and the vertical profile of the main cable. Furthermore, to demonstrate the validity of the simplified analytical method, the unstrained element length method (ULM) is applied to suspension bridge models based on the unstressed lengths of both cable and frame members calculated from the analytical method. Through numerical examples, it is demonstrated that the proposed analytical method can indeed provide an optimized initial solution by showing that both the simplified method and the nonlinear FE procedure lead to practically identical initial configurations with only localized small bending moment distributions.

scholarly journals TWO-NODE CATENARY CABLE ELEMENT WITH RIGID-END EFFECT AND CABLE SHAPE ANALYSIS

2011 ◽  
Vol 11 (03) ◽  
pp. 563-580 ◽  
Author(s):  
Y. B. YANG ◽  
JIUNN-YIN TSAY
Keyword(s):  
Structural Analysis ◽  
Shape Analysis ◽  
Stiffness Matrix ◽  
Suspension Bridge ◽  
Trial And Error ◽  
End Effect ◽  
Flexibility Matrix ◽  
Stay Cables ◽  
The Dead ◽  
Main Cables

The effect of rigid ends is considered in the formulation of a general two-node cable element for the analysis of cable-supported structures. The stiffness matrix of the catenary cable element was derived as the inverse of the flexibility matrix, with allowances for self-weight and pretension effects. In modeling the cables of suspension bridge, distinction is made between single cables (e.g., stay cables and hangers) and multi segment cables (e.g., main cables). The unstressed length of each cable element in terms of the pretension force is determined by a trial-and-error procedure prior to structural analysis. Cable shape analysis was conducted to determine the configuration of main cables for cable-supported bridges under the dead loads. It was demonstrated that the effect of rigid ends cannot be ignored for taut cables, that is, cables with large pretensions. Further, the cable element derived can be reliably used in the analysis of cable-supported bridges, regardless of the sag magnitudes.

Tensile Failure of 55-Nitinol Wire

1975 ◽  
Vol 33 ◽  
pp. 46-47
Author(s):  
F. I. Grace
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Stoichiometric Composition ◽  
Tensile Failure ◽  
Initial State ◽  
Initial Shape ◽  
Nitinol Wire ◽  
Cscl Type ◽  
Shear Transformation

An interest in NiTi alloys with near stoichiometric composition (55 NiTi) has intensified since they were found to exhibit a unique mechanical shape memory effect at the Naval Ordnance Laboratory some twelve years ago (thus refered to as NITINOL alloys). Since then, the microstructural mechanisms associated with the shape memory effect have been investigated and several interesting engineering applications have appeared.The shape memory effect implies that the alloy deformed from an initial shape will spontaneously return to that initial state upon heating. This behavior is reported to be related to a diffusionless shear transformation which takes place between similar but slightly different CsCl type structures.

Control of Vibrations due to Moving Loads on Suspension Bridges

2006 ◽  
Vol 11 (3) ◽  
pp. 293-318 ◽  
Author(s):  
M. Zribi ◽  
N. B. Almutairi ◽  
M. Abdel-Rohman
Keyword(s):  
Bridge Deck ◽  
Suspension Bridge ◽  
Lyapunov Theory ◽  
Dynamic Responses ◽  
Suspension Bridges ◽  
Control Force ◽  
Moving Loads ◽  
Hydraulic Actuator ◽  
Long Span ◽  
Suspended Cables

The flexibility and low damping of the long span suspended cables in suspension bridges makes them prone to vibrations due to wind and moving loads which affect the dynamic responses of the suspended cables and the bridge deck. This paper investigates the control of vibrations of a suspension bridge due to a vertical load moving on the bridge deck with a constant speed. A vertical cable between the bridge deck and the suspended cables is used to install a hydraulic actuator able to generate an active control force on the bridge deck. Two control schemes are proposed to generate the control force needed to reduce the vertical vibrations in the suspended cables and in the bridge deck. The proposed controllers, whose design is based on Lyapunov theory, guarantee the asymptotic stability of the system. The MATLAB software is used to simulate the performance of the controlled system. The simulation results indicate that the proposed controllers work well. In addition, the performance of the system with the proposed controllers is compared to the performance of the system controlled with a velocity feedback controller.

3D CT Cephalometry of Plagiocephaly: Asymmetry and Shape Analysis

2005 ◽  
Author(s):  
David Netherway ◽  
Amanda Abbott ◽  
Nadim Gulamhuseinwala ◽  
Karen McGlaughlin ◽  
Peter Anderson ◽  
...  
Keyword(s):  
Shape Analysis ◽  
3D Ct
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