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.

Performance Assessment Using Structural Analysis and Spatial Measurement of a Damaged Suspension Bridge: Case Study of Twantay Bridge, Myanmar

2018 ◽  
Vol 23 (10) ◽  
pp. 05018008 ◽  
Author(s):  
Koji Matsumoto ◽  
Carlos Arturo Linan Panting ◽  
Nuntikorn Kitratporn ◽  
Wataru Takeuchi ◽  
Kohei Nagai ◽  
...  
Keyword(s):  
Structural Analysis ◽  
Performance Assessment ◽  
Suspension Bridge ◽  
Spatial Measurement

scholarly journals Probabilistic Assessment of the Safety of Main Cables for Long-Span Suspension Bridges considering Corrosion Effects

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Hao Tian ◽  
Jiji Wang ◽  
Sugong Cao ◽  
Yuanli Chen ◽  
Luwei Li
Keyword(s):  
Probability Model ◽  
Steel Wire ◽  
Suspension Bridge ◽  
Element Model ◽  
Traffic Load ◽  
Suspension Bridges ◽  
Accelerated Corrosion ◽  
Long Span ◽  
Accelerated Corrosion Tests ◽  
Main Cables

This paper presents a reliability analysis to assess the safety of corroded main cables of a long-span suspension bridge. A multiscale probability model was established for the resistance of the main cables considering the length effect and the Daniels effect. Corrosion effects were considered in the wire scale by relating the test results from accelerated corrosion tests to the corrosion stages and in the cable scale by adopting a corrosion stage distribution of the main cable section in NCHRP Report 534. The load effects of temperature, wind load, and traffic load were obtained by solving a finite element model with inputs from in-service monitoring data. The so-obtained reliability index of the main cables reduces significantly after operation for over 50 years and falls below the design target value due to corrosion effects on the mechanical properties of the steel wire. Multiple measures should be taken to delay the corrosion effects and ensure the safety of the main cables in the design service life.

scholarly journals Crack Detection through the Change in the Normalized Frequency Shape

Vibration ◽  
2018 ◽  
Vol 1 (1) ◽  
pp. 56-68
Author(s):  
Mustapha Dahak ◽  
Noureddine Touat ◽  
Tarak Benkedjouh
Keyword(s):  
Stiffness Matrix ◽  
Electrical Discharge ◽  
Inverse Method ◽  
Crack Detection ◽  
Natural Frequencies ◽  
Electrical Discharge Machining ◽  
Element Model ◽  
Experimental Application ◽  
Flexibility Matrix ◽  
Crack Position

The objective of this work is to use natural frequencies for the localization and quantification of cracks in beams. First, to study the effect of the crack on natural frequencies, a finite element model of Euler–Bernoulli is presented. Concerning the damaged element, the stiffness matrix is calculated by the theory of fracture mechanics, by inverting the flexibility matrix. Then, in order to detect damage, we are going to show that the shape given by the change in the natural frequencies is as function of the damage position only. Thus, the crack is located by the correlation between the shape of the measured frequencies and those obtained by the finite elements, where the position that gives the calculated shape which is the most similar to the measured one, indicates the crack position. After the localization, an inverse method will be applied to quantify the damage. Finally, an experimental application is presented to show the real applicability of the method, in which the crack is introduced by using an Electrical Discharge Machining. The results confirm the applicability of the method for the localization and the quantification of cracks.

scholarly journals Stress and Shape Analysis of a Paraglider Wing

1965 ◽  
Vol 32 (4) ◽  
pp. 771-780 ◽  
Author(s):  
Robert W. Fralich
Keyword(s):  
Structural Analysis ◽  
Shape Analysis ◽  
Numerical Results ◽  
Internal Stresses ◽  
Flexible Wing ◽  
Aerodynamic Pressure ◽  
Drag Forces ◽  
Lift And Drag ◽  
Drag Ratio ◽  
Lift To Drag Ratio

A combined aerodynamic-structural analysis is made which is based on the assumption that the sail is flexible and has freedom to take the shape which the aerodynamic pressure and the internal stresses dictate. Numerical results were obtained for Newtonian impact aerodynamic theory and were compared with published results obtained for a rigid idealization of the paraglider wing. It was found that the assumed rigid idealization did not approximate the shape of a flexible wing well and led to significant errors in the lift and drag forces and the lift-to-drag ratio. The new calculations provide a basis for design of paragliders for hypersonic flight.

scholarly journals Parametric Study on Responses of a Self-Anchored Suspension Bridge to Sudden Breakage of a Hanger

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Wenliang Qiu ◽  
Meng Jiang ◽  
Cailiang Huang
Keyword(s):  
Suspension Bridge ◽  
Element Model ◽  
Dynamic Responses ◽  
Flexural Stiffness ◽  
Static And Dynamic Analysis ◽  
Main Cable ◽  
Reaction Forces ◽  
Internal Forces ◽  
Torsion Stiffness ◽  
Main Cables

The girder of self-anchored suspension bridge is subjected to large compression force applied by main cables. So, serious damage of the girder due to breakage of hangers may cause the collapse of the whole bridge. With the time increasing, the hangers may break suddenly for their resistance capacities decrease due to corrosion. Using nonlinear static and dynamic analysis methods and adopting 3D finite element model, the responses of an actual self-anchored suspension bridge to sudden breakage of hangers are studied in this paper. The results show that the sudden breakage of a hanger causes violent vibration and large changes in internal forces of the bridge. In the process of the vibration, the maximum tension of hanger produced by breakage of a hanger exceeds 2.22 times its initial value, and the reaction forces of the bearings increase by more than 1.86 times the tension of the broken hanger. Based on the actual bridge, the influences of some factors including flexural stiffness of girder, torsion stiffness of girder, flexural stiffness of main cable, weight of girder, weight of main cable, span to sag ratio of main cable, distance of hangers, span length, and breakage time of hanger on the dynamic responses are studied in detail, and the influencing extent of the factors is presented.

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