A RATIONAL METHOD FOR COMPUTATION OF CABLE STRUCTURES

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Thang Ba Phung ◽  
Lai Tuong Nguyen
Keyword(s):  
High Strength ◽  
Equation System ◽  
Force Balance ◽  
Concentrated Force ◽  
Additional Hypothesis ◽  
Cable Structure ◽  
Cable Structures ◽  
Distributed Forces ◽  
Flexible Cables

Cable structures are widely used in practical construction due to its advantages of light weight, high strength which allow to build large span structures with nice view. The classical theory cable formulated from force balance equation of single cable, that is nonlinear; therefore, to determine displacement, deformation and tension forces of the cable we need to provide cable dip or horizontal tension force and use iteration calculation. This paper presents a new method for computation of flexible cable subjected to different loading pattern including concentrated force, distributed forces, pretension force, temperature variation. By application of the Gaussian Extreme Principle method, which developed by Prof. Drs. Ha Huy Cuong, to formulate and solve nonlinear equation system of cable structures, which ensured forces balancing as well as continuity of displacements and deformations of cable structures. This method allows for simultaneous determination of displacement, deformation and tension forces of cable structure without any other additional hypothesis, which is different from present cable theory. Numerical examples with simple, flexible cables subjected to different loadings have indicated the simplicity, accuracy and stability of the proposed method.

A METHOD FOR STATIC ANALYSIS OF CABLE-STAYED STRUCTURES SUBJECTED TO IN-PLANE LOADS

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Lai Tuong Nguyen ◽  
Thang Ba Phung
Keyword(s):  
Nonlinear Equation ◽  
Static Analysis ◽  
Equation System ◽  
Force Balance ◽  
Virtual Displacement ◽  
Additional Hypothesis ◽  
Cable Theory ◽  
Internal Forces ◽  
Force Balance Equation

Present cable theory which formulated from force balance equation of single cable under self-weight and forms a catenary shape of deflection, that is nonlinear; therefore to determine displacement, deformation and tension forces of the cable and cable-stayed structures we need to provide some additional assumptions of cables and use iteration calculation. This paper presents a new method for static analysis of cable-stayed structures subjected to in-plane loading. By combination of the Gaussian Extreme Principle method and virtual displacement principle, authors to formulate and solve nonlinear equation system of cable-stayed structures, which ensured forces balancing as well as continuity of displacements and deformations of structures. This method allows for simultaneous determination of displacement, deformation and internal forces of cable-stayed structures without any other additional hypothesis, which is different from present cable theory.

Bestimmung der Dauerhaftigkeit von Hochleistungsbeton mit Hilfe des CDF-Tests / Determination of the durability of high performance concrete by means of CDF-test

1999 ◽  
Vol 5 (1) ◽  
pp. 29-40
Author(s):  
R. Krumbach ◽  
U. Schmelter ◽  
K. Seyfarth
Keyword(s):  
Frost Resistance ◽  
High Strength Concrete ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Strength Concrete ◽  
Factors Influencing

Abstract Variable obsen>ations concerning frost resistance of high performance concrete have been made. The question arises which are the decisive factors influencing durability under the action of frost and de-icing salt. The proposed experiments are to be carried out in cooperation with F.A.- Finger - Institute of Bauhaus University Weimar. The aim of this study is to determine possible change of durability of high strength concrete, and to investigate the origin thereof. Measures to reduce the risk of reduced durability have to be found.

High Strength Combined Support Technology in Deep High Stress Soft Rock Roadway

2012 ◽  
Vol 524-527 ◽  
pp. 598-603
Author(s):  
Nian Jie Ma ◽  
Zhi Qiang Zhao ◽  
Hua Zhao ◽  
Li Shuai Jiang
Keyword(s):  
High Stress ◽  
Soft Rock ◽  
High Strength ◽  
Parameter Determination ◽  
Test Results ◽  
Actual Measurement ◽  
Computer Numerical Simulation ◽  
Soft Rock Roadway ◽  
Rock Roadway

In order to solve the serious damage and repeat revision problem of high stress soft rock roadway in deep -950 level of Tangshan coal mine, based on the theory of the maximum stress level, together with the actual measurement of geostress and the laboratory mechanical parameters of rock-core and computer numerical simulation, the high strength combined support technology and supporting parameters are determined and the engineering test has been done. The engineering test results show that the parameter determination of high strength combined support technology, which based on the actual measurement of geostress, can effective solve the support issue of high stress soft rock roadway and provide useful experience for similar engineering problems.

Use of DNVGL-RP-C203 for Determining the Fatigue Capacity of Connectors

2021 ◽  
Author(s):  
Anthony Muff ◽  
Anders Wormsen ◽  
Torfinn Hørte ◽  
Arne Fjeldstad ◽  
Per Osen ◽  
...  
Keyword(s):  
Finite Element ◽  
Fatigue Testing ◽  
Experimental Testing ◽  
High Strength ◽  
Element Model ◽  
Fatigue Analysis ◽  
Full Scale ◽  
The Finite Element Model

Abstract Guidance for determining a S-N based fatigue capacity (safe life design) for preloaded connectors is included in Section 5.4 of the 2019 edition of DNVGL-RP-C203 (C203-2019). This section includes guidance on the finite element model representation, finite element based fatigue analysis and determination of the connector design fatigue capacity by use of one of the following methods: Method 1 by FEA based fatigue analysis, Method 2 by FEA based fatigue analysis and experimental testing and Method 3 by full-scale connector fatigue testing. The FEA based fatigue analysis makes use of Appendix D.2 in C203-2019 (“S-N curves for high strength steel applications for subsea”). Practical use of Section 5.4 is illustrated with a case study of a fatigue tested wellhead profile connector segment test. Further developments of Section 5.4 of C203-2019 are proposed. This included acceptance criteria for use of a segment test to validate the FEA based fatigue analysis of a full-scale preloaded connector.

Cavitation Inception Behind a Jet-Propelled Body

2007 ◽  
Author(s):  
William Hambleton ◽  
Eduard Amromin ◽  
Roger E. A. Arndt ◽  
Svetlana Kovinskaya
Keyword(s):  
Velocity Ratio ◽  
The Body ◽  
Force Balance ◽  
Water Tunnel ◽  
Minimum Diameter ◽  
Cavitation Inception ◽  
Initial Comparison ◽  
Jet Velocity ◽  
Good Agreement

Cavitation inception behind an axissymmetric body driven by a waterjet has been studied experimentally and numerically. Water tunnel tests have been performed with the body mounted on a force balance. The transom of the body contained a nozzle located along the centerline. Tests were carried out for various water tunnel speeds such that jet velocity ratio, VJ/U, could be varied in the range 0 to 2. Distinctly different cavitation patterns were observed at zero jet velocity (when cavitation appeared in spiral vortices in such flows) and at a various jet velocity ratios (when cavitation appeared between counter-rotating vortices around the jet in such flows). Cavitation inception/disappearance has been determined visually. The body drag was also measured. An analytical method for determination of cavitation inception index has been developed on the basis of a viscous-inviscid interaction concept, with employment of special semiempirical approximations for vortices and consideration of surface tension. These approximations have been preliminarily validated for nozzle jet cavitation (for nozzle discharge in co-flow). It was assumed that visualization allows detection of cavities (bubbles) of 0.4mm-0.5mm diameter or larger. The cavitation inception index is defined as the cavitation index for cavities of such minimum diameter when these cavities are located between counter-rotating vortices. The initial comparison of predicted and measured values of the cavitation inception index shows good agreement.

Experimental Study of Stress Corrosion of High-Strength Wires Affected by Four Typical Ions

2012 ◽  
Vol 226-228 ◽  
pp. 1597-1603 ◽  
Author(s):  
Jian Guo Yin ◽  
Chu Han Deng ◽  
Yu Guang Fu ◽  
Liu Chi Li
Keyword(s):  
Experimental Study ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Stress Corrosion ◽  
Acid Rain ◽  
Crack Growth ◽  
High Strength ◽  
Major Effect ◽  
Light Weight ◽  
Cable Structures

Characterized by light weight and high strength, cold-drawn galvanized cable wires are widely applied in all kinds of prestressed structures and cable structures. Investigation shows that cables are sensitive to corrosion. Severe corrosion of cables results in cable replacement which are costly, and even more, collapse of the whole bridge. In this paper, several tests were carried out to present the crack growth of wire in stress corrosion in different solutions. In particular, as Cl-, OH-, SO42- and NH4+ have major effect on stress corrosion in seawater and acid rain, these four kinds of ions are selected in tests. And all four kinds of corrosive solutions are tested with the concentration of 1.5 bsp and 3 bsp respectively. Effects on ultimate tensile strength and sensitivity of cable wires are different for each of chosen ions, and the increasing concentration for the same solution would drop ultimate tensile strength and the modulus of cable wires.

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