Analytical prediction of lateral-torsional buckling of long-span suspension bridge

In this paper, the lateral torsional buckling (LTB) behavior of multi-layered long-span laminated glass (LG) beams is investigated through full-scale model test and numerical simulation. In the test program, the LG beams consisting of up to four glass plies and spanning 5000[Formula: see text]mm are constructed and tested. The load-displacement curves and development of strain in glass plies are recorded, based on which the deformation and stress state of buckled LG beams are analyzed, and the strength checking criterion is provided. The test results are also used to determine the shape and amplitude of initial imperfection through statistical analysis and to validate a numerical model based on the finite element method (FEM). Parametric analysis based on the FEM model is then conducted to investigate influential factors on the LTB resistance of LG beams, among which the influence of shape and amplitude of initial imperfection is emphasized. For the LTB design of LG beams, the applicability of existing formula to determine the critical buckling moment through effective stiffnesses is evaluated for multi-layered LG beams with the test and numerical results. Finally, the design buckling curves adopting the Ayrton–Perry formula (APF) are proposed and validated for LG beams categorized with glass type and load duration.

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STUDI EKSPERIMENTAL KUAT LENTUR BAJA PROFIL I KOMPAK SIMETRIS GANDA BERDASARKAN RSNI 03-1729-201X

Forum Mekanika ◽

10.33322/forummekanika.v6i2.122 ◽

1970 ◽

Vol 6 (2) ◽

pp. 99-105

Author(s):

Redaksi Tim Jurnal

Keyword(s):

Flexural Strength ◽

Cross Section ◽

Experimental Testing ◽

Point Load ◽

National Standard ◽

Lateral Torsional Buckling ◽

Torsional Buckling ◽

Element Analysis ◽

Long Span ◽

The Stability

The danger of buckling and instability structures easily occurs on the steel beam structure, it will make the structure fails before it reaches the cross section ultimate capacity.In that case the strength of a beam is not only determined by cross-section ultimate capacity. The instability of the structure causes lateral torsional buckling eventhough there is no torque on the beam. There is one way to support the stability of the beam; by installing lateral support on its side. This research is intended to obtain information about flexural strength by comparing the theoretical results based on SNI 03-1729-2002 and (Indonesian National Standard Draft) RSNI 03-1729.1- 201x with the results of experimental testing and finite element analysis results (using the ABAQUS program). The flexural specimens which are studied are in the long-span with a length of 3.3 meters span test. The loading uses three-point load system. The results of the test show information that flexural strength for the long-span specimen from experimental test results has the smallest difference of 33.18% of the theoretical result. As for analysis with FEM also hasthe same difference of 33.18% with the experimental results. Failure that occurs for long-span specimen is due to lateral torsional buckling failures.

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Control of Vibrations due to Moving Loads on Suspension Bridges

Nonlinear Analysis Modelling and Control ◽

10.15388/na.2006.11.3.14749 ◽

2006 ◽

Vol 11 (3) ◽

pp. 293-318 ◽

Cited By ~ 4

Author(s):

M. Zribi ◽

N. B. Almutairi ◽

M. Abdel-Rohman

Keyword(s):

Bridge Deck ◽

Suspension Bridge ◽

Lyapunov Theory ◽

Dynamic Responses ◽

Suspension Bridges ◽

Control Force ◽

Moving Loads ◽

Hydraulic Actuator ◽

Long Span ◽

Suspended Cables

The flexibility and low damping of the long span suspended cables in suspension bridges makes them prone to vibrations due to wind and moving loads which affect the dynamic responses of the suspended cables and the bridge deck. This paper investigates the control of vibrations of a suspension bridge due to a vertical load moving on the bridge deck with a constant speed. A vertical cable between the bridge deck and the suspended cables is used to install a hydraulic actuator able to generate an active control force on the bridge deck. Two control schemes are proposed to generate the control force needed to reduce the vertical vibrations in the suspended cables and in the bridge deck. The proposed controllers, whose design is based on Lyapunov theory, guarantee the asymptotic stability of the system. The MATLAB software is used to simulate the performance of the controlled system. The simulation results indicate that the proposed controllers work well. In addition, the performance of the system with the proposed controllers is compared to the performance of the system controlled with a velocity feedback controller.

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