GEOMETRIC NONLINEAR ANALYSIS OF CABLE STRUCTURES WITH A TWO-NODE CABLE ELEMENT BY GENERALIZED DISPLACEMENT CONTROL METHOD

2007 ◽  
Vol 07 (04) ◽  
pp. 571-588 ◽  
Author(s):  
Y. B. YANG ◽  
JIUNN-YIN TSAY
Keyword(s):  
Nonlinear Analysis ◽  
Stiffness Matrix ◽  
Control Method ◽  
Three Dimensional ◽  
Suspension Bridges ◽  
Single Element ◽  
Long Span ◽  
Geometric Nonlinear ◽  
Generalized Displacement Control Method ◽  
Geometric Nonlinear Analysis

This paper presents a two-node catenary cable element for the analysis of three-dimensional cable-supported structures. The stiffness matrix of the catenary cable element was derived as the inverse of the flexibility matrix, with allowances for selfweight and pretension effects. The element was then included, along with the beam and truss elements, in a geometric nonlinear analysis program, for which the procedure for computing the stiffness matrix and for performing iterations was clearly outlined. With the present element, each cable with no internal joints can be modeled by a single element, even for cables with large sags, as encountered in cable nets, suspension bridges and long-span cable-stayed bridges. The solutions obtained for all the examples are in good agreement with the existing ones, which indicates the accuracy and applicability of the element presented.

Feasibility Study of Super-Long Span Bridges Considering Aerostatic Instability by a Two-Stage Geometric Nonlinear Analysis

2020 ◽  
pp. 2150033
Author(s):  
Jiunn-Yin Tsay
Keyword(s):  
Wind Speed ◽  
Nonlinear Analysis ◽  
Two Stage ◽  
Long Span Bridges ◽  
Critical Wind Speed ◽  
Long Span ◽  
Main Cable ◽  
Geometric Nonlinear ◽  
Long Span Bridge ◽  
Geometric Nonlinear Analysis

To meet the need of constructing fixed cross strait links, super-long span bridge with a main span over 2 000[Formula: see text]m is considered as a candidate for their ability to cross deep and wide straits. To this end, some super-long span bridges with proper cable and girder systems were previously proposed and studied. The major design considerations are aimed at adopting new cable material, increasing the entire rigidity of the bridge, stabilizing the dynamic characteristics, strengthening the deck sections, etc. In this paper, a brief review of main cable and girder system is first given of the concepts previously proposed for the design of super-long span bridges. Then some typical examples are studied, focused on various issues related to the design of super-long span bridges, including composite cable, the unstressed length and tension force of the main cable, the stiffness and mass effects of the deck on critical wind speed, and the critical wind speed of various cable systems. The most challenges in super-long span bridges are to solve aerostatic and aerodynamic instability at required design wind speed. In this connection, the wind-induced aerostatic instability of super-long span bridges is studied by a two-stage geometric nonlinear analysis for dead loads and wind loads. The developed program adopted herein for geometric nonlinear analysis was verified and confirmed before. The proposed methods (i.e. composite cable, slotted girder, increasing deck stiffness and mass, cable layout, etc.) obtained for all the examples are in agreement with this study, which indicates applicability of the design approaches presented.

Recent developments in geometrically nonlinear and postbuckling analysis of framed structures

2003 ◽  
Vol 56 (4) ◽  
pp. 431-449 ◽  
Author(s):  
Yeong-Bin Yang ◽  
Jong-Dar Yau ◽  
Liang-Jenq Leu
Keyword(s):  
Rigid Body ◽  
Nonlinear Analysis ◽  
Stiffness Matrix ◽  
Truss Structures ◽  
Simple Extension ◽  
Framed Structures ◽  
Geometric Stiffness ◽  
Geometric Nonlinear ◽  
Iterative Analysis ◽  
Geometric Nonlinear Analysis

Geometric nonlinear analysis of structures is not a simple extension from its counterpart of linear analysis. In this article, some research works conducted primarily in the past two decades on the geometric nonlinear analysis of framed structures that are readily available to the authors, including, in particular, those conducted by the senior author and coworkers, will be briefly reviewed. To highlight the key features of geometric nonlinear analysis, each of the papers cited will be reviewed according to one or more of the following categories: a) analytical or semi-analytical works, b) formulation of incremental nonlinear theory, c) discrete vs connected element and procedure of assembly, d) joint equilibrium conditions in the deformed configuration, e) rigid body test for nonlinear finite elements, f) key phases in incremental-iterative analysis, g) force recovery procedure, h) strategy for incremental-iterative approaches, i) rigid body-qualified geometric stiffness matrix, j) formulation and simulation for curved beam problems, k) special considerations for truss structures, and l) other related considerations. Throughout this article, emphasis will be placed on the theories and procedures leading to solution of the load-deflection response of structures, which may involve multi-looping curves in the postbuckling range. In fact, a nonlinear analysis using incremental-iterative schemes need not be as complicated as we think. If due account can be taken of the rigid body behaviors at each stage, then the whole process of incremental-iterative analysis can be made simpler and more efficient. Even when the postbuckling behavior of structures is of concern, the use of an accurate elastic stiffness matrix plus a rigid-body-qualified geometric stiffness matrix can always yield satisfactory results. There are 122 references cited in this review article.

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