Simplified Calculation of Pylon Top Displacement of Multi-Pylon Suspension Bridge

The long-span multi-pylon suspension bridge is the subject of growing interest. Under live load, the longitudinal deflection of the mid-pylon is an important control parameter for a multi-pylon suspension bridge design. It is important to establish a simplified method of calculating pylon deflection for the preliminary design and selection of a multi-pylon suspension bridge. Based on deflection theory and deformation compatibility condition, considering main cable horizontal constraints and the interaction among pylons and girders with the methods of equivalent stiffness and moment distribution, the simplified calculation formulas of pylon displacement at the top for three-, four-, and five-pylon suspension bridges are derived. The validity of the formulas are verified by model experiment, real bridge testing, and finite-element analysis. For a floating system, the error between the simplified formula and the finite element method is less than 10%, and that of the model experiment is within 25%. For a consolidation system, the error between the simplified formula and the finite element method is within 16%, and that of the real bridge testing is less than 11%. As the number of pylons increases, the simplified formulas tend to be less accurate.

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

Advances in Structural Engineering ◽

10.1177/1369433218820243 ◽

2018 ◽

Vol 22 (7) ◽

pp. 1566-1578 ◽

Cited By ~ 4

Author(s):

Wen-ming Zhang ◽

Tao Li ◽

Lu-yao Shi ◽

Zhao Liu ◽

Kai-rui Qian

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Iterative Method ◽

Numerical Test ◽

Iteration Process ◽

Suspension Bridge ◽

Suspension Bridges ◽

Tensile Forces ◽

Main Cables ◽

Element Method

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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Simulation of tuning graphene plasmonic behaviors by ferroelectric domains for self-driven infrared photodetector applications

Nanoscale ◽

10.1039/c9nr06508c ◽

2019 ◽

Vol 11 (43) ◽

pp. 20868-20875 ◽

Cited By ~ 1

Author(s):

Junxiong Guo ◽

Yu Liu ◽

Yuan Lin ◽

Yu Tian ◽

Jinxing Zhang ◽

...

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Interfacial Effect ◽

Infrared Photodetector ◽

The Finite Element Method ◽

Ferroelectric Domains ◽

Element Method

We propose a graphene plasmonic infrared photodetector tuned by ferroelectric domains and investigate the interfacial effect using the finite element method.

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