Form-finding analysis of suspension bridges using an explicit Iterative approach

Cao, Hongyou; Zhou, Yunlai; Chen, Zhijun; Wahab, Magd Abdel

doi:10.12989/sem.2017.62.1.085

Cited by 32 publications

(6 citation statements)

References 18 publications

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“…Sensitivity analysis is a reliable method of structural analysis. Cao et al [16] even combined sensitivity analysis and the Jacobian matrix to perform an iterative form-finding analysis for the main cable of a suspension bridge.…”

Section: Introductionmentioning

confidence: 99%

Cable Interlayer Slip Damage Identification Based on the Derivatives of Eigenparameters

Zhong

Yan

Liu

et al. 2018

Sensors

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Cables are the main load-bearing structural components of long-span bridges, such as suspension bridges and cable-stayed bridges. When relative slip occurs among the wires in a cable, the local bending stiffness of the cable will significantly decrease, and the cable enters a local interlayer slip damage state. The decrease in the local bending stiffness caused by the local interlayer slip damage to the cable is symmetric or approximately symmetric for multiple elements at both the fixed end and the external load position. An eigenpair sensitivity identification method is introduced in this study to identify the interlayer slip damage to the cable. First, an eigenparameter sensitivity calculation formula is deduced. Second, the cable is discretized as a mass-spring-damping structural system considering stiffness and damping, and the magnitude of the cable interlayer slip damage is simulated based on the degree of stiffness reduction. The Tikhonov regularization method is introduced to solve the damage identification equation of the inverse problem, and artificial white noise is introduced to evaluate the robustness of the method to noise. Numerical examples of stayed cables are investigated to illustrate the efficiency and accuracy of the method proposed in this study.

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Section: Introductionmentioning

confidence: 99%

Cable Interlayer Slip Damage Identification Based on the Derivatives of Eigenparameters

Zhong

Yan

Liu

et al. 2018

Sensors

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“…In order to verify how well the proposed analytical method predicts the cable geometry with known hanger tensions, the Great Belt suspension bridge is selected as a verification example. This problem was first considered by Karoumi (1999), and later analyzed by Kim and Lee (2001), Kim and Kim (2012), and Cao et al (2017). The length of the main span is 1624 m. The cable sag in the main span is 180 m. The structural model used in this study mostly follows Karoumi’s model (Karoumi 1999), in which every third hanger from the original bridge is included.…”

Section: Verification Studymentioning

confidence: 99%

“…The former techniques identify the curved shape of the target cable by updating the nodal positions and tensile forces of the cable catenary elements through the nonlinear structural analysis via the Newton iterations (Cao et al, 2017; Chen et al, 2000, 2013; Hassan, 2013; Karoumi, 1999; Kim et al, 2002; Kim and Kim, 2012; Kim and Lee, 2001; Lu et al, 2014). In contrast to the catenary-element-based methods, the analytical techniques possess a much higher computational efficiency and a faster convergence (Cao et al, 2017). Over the past decades, the analytical approaches for cable shape-finding have been significantly improved based on either the segmental parabola theory or the segmental catenary theory.…”

Section: Introductionmentioning

confidence: 99%

An iterative calculation method for hanger tensions and the cable shape of a suspension bridge based on the catenary theory and finite element method

Zhang

Shi

et al. 2018

Advances in Structural Engineering

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Construction of suspension bridges and their structural analysis are challenged by the presence of elements (chains or main cables) capable of large deflections leading to a geometric nonlinearity. For an accurate prediction of the main cable geometry of a suspension bridge, an innovative iterative method is proposed in this article. In the iteration process, hanger tensions and the cable shape are, in turns, used as inputs. The cable shape is analytically predicted with an account of the pylon saddle arc effect, while finite element method is employed to calculate hanger tensions with an account of the combined effects of the cable-hanger-stiffening girder. The cable static equilibrium state is expressed by three coupled nonlinear governing equations, which are solved by their transformation into a form corresponding to the unconstrained optimization problem. The numerical test results for the hanger tensions in an existing suspension bridge were obtained by the proposed iterative method and two conventional ones, namely, the weight distribution and continuous multiple-rigid-support beam methods. The latter two reference methods produced the respective deviations of 10% and 5% for the side hangers, respectively, which resulted in significant errors in the elevations of the suspension points. To obtain more accurate hanger tensile forces, especially for the side hangers, as well as the cable shape, the iterative method proposed in this article is recommended.

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“…Maintaining the health of civil infrastructures such as bridges, roads, and tunnels is important to achieve a safe and reliable society [1][2][3]. Because a large number of concrete structures were built in the age of rapid economic growth in Japan, many of them are approaching their designed life spans.…”

Section: Introductionmentioning

confidence: 99%

On-Site Bridge Inspection by 950 keV/3.95 MeV Portable X-Band Linac X-Ray Sources

Uesaka¹,

Mitsuya²,

Dobashi³

et al. 2020

Bridge Optimization - Inspection and Condition Monitoring

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Many bridges around the world face aging problems and degradation of structural strength. Visual and hammering sound inspections are under way, but the status of inner reinforced iron rods and prestressed concrete (PC) wires has not yet been confirmed. Establishing a diagnosis method for bridges based on X-ray visualization is required to evaluate the health of bridges accurately and to help with the rationalization of bridge maintenance. We developed 950 keV/3.95 MeV X-band electron linac-based X-ray sources for on-site bridge inspection and visualized the inner structure of a lower floor slab. The information regarding wire conditions by X-ray results was used for the structural analysis of a bridge to evaluate its residual strength and sustainability. For more precise inspection of wire conditions, we applied three-dimensional image reconstruction methods for bridge mock-up samples. Partial-angle computed tomography (CT) and tomosynthesis provided cross-sectional images of the samples at 1 mm resolutions. Image processing techniques such as the curvelet transform were applied to evaluate diameter of PC wires by suppressing noise. Technical guidelines of bridge maintenance using the 950 keV/3.95 MeV X-ray sources are proposed. We plan to offer our technique and guidelines for safer and more reliable maintenance of bridges around the world.

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Form-finding analysis of suspension bridges using an explicit Iterative approach

Cited by 32 publications

References 18 publications

Cable Interlayer Slip Damage Identification Based on the Derivatives of Eigenparameters

Cable Interlayer Slip Damage Identification Based on the Derivatives of Eigenparameters

An iterative calculation method for hanger tensions and the cable shape of a suspension bridge based on the catenary theory and finite element method

On-Site Bridge Inspection by 950 keV/3.95 MeV Portable X-Band Linac X-Ray Sources

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