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Article
Publication date: 7 January 2019

Jiandong Wei, Manyu Guan, Qi Cao and Ruibin Wang

The purpose of this paper is to analyze the cable-supported bridges more efficiently by building the finite element model with the spatial combined cable element.

Abstract

Purpose

The purpose of this paper is to analyze the cable-supported bridges more efficiently by building the finite element model with the spatial combined cable element.

Design/methodology/approach

The spatial combined cable element with rigid arms and elastic segments was derived. By using the analytical solution of the elastic catenary to establish the flexibility matrix at the end of the cable segment and adding it to the flexibility matrix at the ends of the two elastic segments, the flexibility matrix at the end of the cable body is obtained. Then the stiffness matrix of the cable body is established and the end force vector of cable body is given. Using the displacement transformation relationship between the two ends of the rigid arm, the stiffness matrix of the combined cable element is derived. By assigning zero to the length of the elastic segment(s) or/and the rigid arm(s), many subdivisions of the combined cable element can be obtained, even the elastic catenary element.

Findings

The examples in this field and specially designed examples proved the correctness of the proposed spatial combined cable element.

Originality/value

The combined cable element proposed in this study can be used for the design and analysis of cable-stayed bridges. Case studies show that it is able to simulate cable accurately and could also be used to simulate the suspenders in arch bridges as well in suspension bridges.

Details

Engineering Computations, vol. 36 no. 1
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 1 July 2014

Petros Christou, Antonis Michael and Miltiades Elliotis

The purpose of this paper is to present a solution strategy for the analysis of cable networks which includes an extension to the force density method (FDM) in an attempt…

Abstract

Purpose

The purpose of this paper is to present a solution strategy for the analysis of cable networks which includes an extension to the force density method (FDM) in an attempt to support cable elements when they become slack. The ability to handle slack cable elements in the analysis is particularly important especially in cases where the original cable lengths are predefined, i.e. the cable structure has already been constructed, and there is a need for further analysis to account for additional loading such as wind. The solution strategy is implemented in a software application.

Design/methodology/approach

The development of the software required the implementation of the FDM for the analysis of cable networks and its extension to handle constraints. The implemented constraints included the ability to preserve the length in the stressed or the unstressed state of predefined cable elements. In addition, cable statics are incorporated with the development of the cable equation and its modification to be able to be handled by the FDM .

Findings

The implementation of the solution strategy is presented through examples using the software which has been developed for these purposes.

Originality/value

The results suggest that for cable networks spanning large distances or cable elements with considerable self-weight the neglect of the cable slackening effects is not always conservative.

Details

Engineering Computations, vol. 31 no. 5
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 7 March 2016

Liang Zhang, Qiang Gao, Yin Liu and Hongwu Zhang

The purpose of this paper is to propose an efficient finite element formulation for nonlinear analysis of clustered tensegrity that consists of classical cables, clustered…

Abstract

Purpose

The purpose of this paper is to propose an efficient finite element formulation for nonlinear analysis of clustered tensegrity that consists of classical cables, clustered cables and bars.

Design/methodology/approach

The derivation of the finite element formulation is based on the co-rotational approach, which decomposes a geometrically nonlinear deformation into a large rigid body motion and a small-strain deformation. A tangent stiffness matrix of a clustered cable is proposed and the Newton-Raphson scheme is employed to solve the nonlinear equation.

Findings

The derived tangent stiffness matrix, including an additional stiffness terms that describes the slide effect of pulleys, can regress to the stiffness matrix of a classical cable, which is convenient for the implementation of finite element procedure. Two typical numerical examples show that the proposed formulation is accurate and requires less iteration than the force density method.

Originality/value

The co-rotational formulation of a clustered cable is originally proposed, although some mature methods, such as the TL, Force Density and Dynamic Relaxation method, have been applied to nonlinear analysis of clustered tensegrity. The proposed co-rotational formulation proved efficient.

Details

Engineering Computations, vol. 33 no. 1
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 30 May 2008

Wei‐Xin Ren, Meng‐Gang Huang and Wei‐Hua Hu

The purpose of this paper is to present a finite element formulation of enhanced two‐node parabolic cable element for the static analysis of cable structures.

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Abstract

Purpose

The purpose of this paper is to present a finite element formulation of enhanced two‐node parabolic cable element for the static analysis of cable structures.

Design/methodology/approach

Unlike the assumed polynomial displacement interpolation functions, the present approach uses the analytical cable dynamic stiffness matrix to obtain the explicit expression of the static stiffness matrix of an inclined sagging cable by setting the frequency at zero. The Newton‐Raphson‐based iterative method is used to obtain the solution.

Findings

It is demonstrated that the present results agree well with those obtained from the nonlinear analytical theory of a parabolic cable and previous reported methods in the literature.

Originality/value

This paper proposes a two‐node parabolic cable element. For comparable accuracy with the truss element method, fewer numbers of such cable elements are needed.

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Article
Publication date: 27 May 2014

Ming-Yi Liu, Li-Chin Lin and Pao-Hsii Wang

The purpose of this paper is to provide a variety of viewpoints to illustrate the mechanism of the deck-stay interaction with the appropriate initial shapes of cable

Abstract

Purpose

The purpose of this paper is to provide a variety of viewpoints to illustrate the mechanism of the deck-stay interaction with the appropriate initial shapes of cable-stayed bridges, which is validated by a symmetrical structure.

Design/methodology/approach

Based on the smooth and convergent bridge shapes obtained by the initial shape analysis, the one-element cable system (OECS) and multi-element cable system (MECS) models of the symmetric harp cable-stayed bridge are developed to verify the applicability of the analytical model and numerical formulation from the field observations in the authors’ previous work. For this purpose, the modal analyses of the two finite element models are conducted to calculate the natural frequency and normalized mode shape of the individual modes of the bridge. The modal coupling assessment is also performed to obtain the generalized mass ratios among the structural components for each mode of the bridge.

Findings

The findings indicate that the coupled modes are attributed to the frequency loci veering and mode localization when the “pure” deck-tower frequency and the “pure” stay cable frequency approach one another, implying that the mode shapes of such coupled modes are simply different from those of the deck-tower system or stay cables alone. The distribution of the generalized mass ratios between the deck-tower system and stay cables are useful indices for quantitatively assessing the degree of coupling for each mode. For each identical group of stay cables in the MECS model, the local modes with similar natural frequencies and normalized mode shapes consist of the participation of one or more stay cables. These results are demonstrated to fully understand the mechanism of the deck-stay interaction with the appropriate initial shapes of cable-stayed bridges.

Originality/value

It is important to investigate the deck-stay interaction with the appropriate initial shape of a cable-stayed bridge. This is because such initial shape not only reasonably provides the geometric configuration as well as the prestress distribution of the bridge under the weight of the deck-tower system and the pretension forces in the stay cables, but also definitely ensures the satisfaction of the relations for the equilibrium conditions, boundary conditions and architectural design requirements. However, few researchers have studied the deck-stay interaction considering the initial shape effect. The objective of this paper is to fully understand the mechanism of the deck-stay interaction with the appropriate initial shapes of cable-stayed bridges, which is validated by a symmetrical structure. The modal coupling assessment is also performed for quantitatively assessing the degree of coupling for each mode of the bridge.

Details

Engineering Computations, vol. 31 no. 4
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 4 January 2016

Yue Zhang, Cheng Wei, Dong Pan and Yang Zhao

– The purpose of this paper is to provide an accurate dynamic model for the flexible cable capture mechanism and to analyze the dynamic characteristics in the capturing process.

Abstract

Purpose

The purpose of this paper is to provide an accurate dynamic model for the flexible cable capture mechanism and to analyze the dynamic characteristics in the capturing process.

Design/methodology/approach

The absolute nodal coordinate formulation (ANCF) that based on the continuum mechanics approach is applied in the capture task using flexible cables. An ANCF cable element in which axial and bending strain energy are taken into account is presented to model the flexible cables. The generalized coordinates of ANCF are absolute displacements and slopes and make no small deformation assumptions; therefore, this element has a remarkable superiority in the large rotation and deformation analysis of flexible cables compared to the conventional floating frame of reference formulation (FFRF). The mass matrix of the cable element is constant, which will reduce the degree of non-linearity of the dynamic equations. The contact force between the steel cables and capture rod is calculated by the non-linear contact dynamic model, in which material and geometry properties of contact bodies are considered.

Findings

The stress distribution of steel cables is investigated in the numerical studies which show that the closer to the ends of the cable, the larger axial forces and smaller bending moments they will be. The reduction of grasping velocity will lead to a decrease in the contact force and the oversize peak value of contact force is more likely to be avoided when reducing the elastic modulus of steel cables to obtain a greater soft capture capability.

Practical implications

The work shows a practical possibility to improve modeling accuracy of the capture mechanism. Results of the analyses can provide references for the design and analysis of the capture task.

Originality/value

The ANCF is first used in the analysis of the capture task with flexible cables, and some useful results which have not been published before are obtained.

Details

Aircraft Engineering and Aerospace Technology: An International Journal, vol. 88 no. 1
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 6 April 2010

Jin Cheng

The existing methods for determining cable forces in cable‐stayed bridges constructed are based on assumption of complete determinacy of structural parameters. This is…

Abstract

Purpose

The existing methods for determining cable forces in cable‐stayed bridges constructed are based on assumption of complete determinacy of structural parameters. This is usually referred to as deterministic analysis. But in reality there are uncertainties in design variables. These uncertainties include geometric properties (cross‐sectional properties and dimensions), material mechanical properties (modulus and strength, etc), load magnitude and distribution, etc. Thus deterministic analysis cannot provide complete information regarding cable forces in cable‐stayed bridges constructed. The purpose of this paper is to determine cable forces in cable‐stayed bridges constructed under parametric uncertainty.

Design/methodology/approach

An efficient and accurate algorithm is proposed to determine the cable forces in cable‐stayed bridges constructed under parameter uncertainty. The proposed method is a hybrid method, consisting of the improved Monte Carlo simulation method and forward process analysis method.

Findings

The proposed algorithm can obtain more information about the cable forces at different construction stages than the commonly used deterministic method, and it provides an improved understanding of the cable forces in cable‐stayed bridges constructed with parameter uncertainties.

Originality/value

The values of this type of research are that: it developed an efficient and accurate algorithm for determining the cable forces in cable‐stayed bridges constructed under parameter uncertainty; and it provided an improved understanding of the cable forces in cable‐stayed bridges constructed with parameter uncertainties.

Details

Engineering Computations, vol. 27 no. 3
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 1 June 1997

Jaroslav Mackerle

Gives a bibliographical review of the finite element methods (FEMs) applied for the linear and nonlinear, static and dynamic analyses of basic structural elements from the…

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5236

Abstract

Gives a bibliographical review of the finite element methods (FEMs) applied for the linear and nonlinear, static and dynamic analyses of basic structural elements from the theoretical as well as practical points of view. The range of applications of FEMs in this area is wide and cannot be presented in a single paper; therefore aims to give the reader an encyclopaedic view on the subject. The bibliography at the end of the paper contains 2,025 references to papers, conference proceedings and theses/dissertations dealing with the analysis of beams, columns, rods, bars, cables, discs, blades, shafts, membranes, plates and shells that were published in 1992‐1995.

Details

Engineering Computations, vol. 14 no. 4
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 30 August 2021

Lifeng Wang, Huijiang Qu, Longlong Sun, Ziwang Xiao, Long Liu and Sharf Shajib Ahmad

Due to the deformation between the pylon and the girder caused by single tension of cables, the previously tensioned steel strands have stress relaxation, resulting in the…

Abstract

Purpose

Due to the deformation between the pylon and the girder caused by single tension of cables, the previously tensioned steel strands have stress relaxation, resulting in the actual cable forces being less than the design cable forces. To compensate the stress loss caused by the single tension of cables, this paper aims to present a practical compensation algorithm of stress relaxation during the construction period.

Design/methodology/approach

From the perspective of the essential cause of the stress relaxation, finite element analysis is used to solve the tension control force of each steel strand after a rigorous theoretical formula derivation.

Findings

The deformation and tension control force of each steel strand decrease with the advance of the tension sequence, and the decline rate drops gradually. However, the calculated force values of the steel strand are in good agreement with the measured value as the cable length decreases.

Originality/value

The previous rough calculation methods for the tension force of steel strands cannot meet the accuracy, and the accurate calculation methods often include the solution of nonlinear equations, which complicate the calculating process. Otherwise, there are few studies on the compensation of stress loss by calculating the deformation of the steel strand during the tension process. So, it developed an accurate and efficient algorithm to determine the tension control forces.

Details

Multidiscipline Modeling in Materials and Structures, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1573-6105

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Article
Publication date: 1 January 1985

Pál G. Bergan, Egil Mollestad and Nils Sandsmark

A method for non‐linear static and dynamic analysis of flexible systems submerged in water is outlined. The systems considered here include cable and beam elements, as…

Abstract

A method for non‐linear static and dynamic analysis of flexible systems submerged in water is outlined. The systems considered here include cable and beam elements, as well as buoys and clump weights. Contact and lift‐off between members and the sea floor is also accounted for. The formulation used allows for very large deformations and material non‐linearities. Hydrostatic buoyancy and hydrodynamic drag forces are considered throughout the analyses. These capabilities have been implemented in the general purpose non‐linear finite element program FENRIS. Aspects concerning efficient solution of the non‐linear static and dynamic equations are discussed. In particular, an efficient start‐up procedure for analysis of highly flexible systems is described. The paper shows applications involving static and dynamic analysis of a floating structure kept in place by six mooring lines and a flexible riser system.

Details

Engineering Computations, vol. 2 no. 1
Type: Research Article
ISSN: 0264-4401

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