Existence and stability of large scale nonlinear oscillations in suspension bridges

1989 ◽  
Vol 40 (2) ◽  
pp. 172-200 ◽  
Author(s):  
J. Glover ◽  
A. C. Lazer ◽  
P. J. McKenna
Keyword(s):  
Large Scale ◽  
Nonlinear Oscillations ◽  
Suspension Bridges ◽  
Existence And Stability

The Existence and Stability of Ultraharmonics and Subharmonics in Forced Nonlinear Oscillations

1954 ◽  
Vol 21 (4) ◽  
pp. 327-335
Author(s):  
T. K. Caughey
Keyword(s):  
Nonlinear Oscillations ◽  
Initial Conditions ◽  
Forced Oscillations ◽  
Order System ◽  
Response Curves ◽  
Restoring Force ◽  
Amplitude Frequency Response ◽  
Existence And Stability ◽  
Linearized Theory ◽  
The Stability

Abstract A study is made of the forced oscillations of a second-order system having a small cubic nonlinearity in the restoring force. It is shown that under suitable conditions ultraharmonic or subharmonic motion exists in addition to the harmonic motion which a linearized theory would predict. By studying the stability of such motions it is shown that at points on the amplitude frequency-response curves having vertical tangents, instability and consequently “jumps” occur. A study of the dependence of the motion on the initial conditions reveals that while ultra-harmonic and harmonic motions are rather insensitive to initial conditions, the existence of subharmonic motion can be achieved only for a restricted set of initial conditions.

scholarly journals STABILITY ANALYSIS OF THE GRAVITY ANCHORAGE OF A SUSPENSION BRIDGE BASED ON LARGE-SCALE FIELD TESTS

2021 ◽  
Vol 30 (1) ◽  
Author(s):  
Zhijun Zhou ◽  
Chaoran Chen ◽  
Longfei Wang ◽  
Yeqing Tian ◽  
Hongming Feng ◽  
...  
Keyword(s):  
Contact Stress ◽  
Large Scale ◽  
Field Tests ◽  
Stability Study ◽  
Bottom Surface ◽  
Suspension Bridges ◽  
Stability Coefficient ◽  
Finite Element Software ◽  
The Stability ◽  
Main Cables

The stability of gravity anchorages is critical to the safe operation of suspension bridges. The purpose of this paper is to study the stability of a gravity anchorage under the tension of main cables. Large-scale load tests and direct shear tests under the nature state and the saturated state were carried out in the adit at the bottom of the gravity anchorage, because the bottom surface of the gravity anchorage is below the design water level of a reservoir to be built. Representative rock samples in the anchorage area were selected for indoor tests. The basic parameters of the rock mass and the characteristic value of subsoil bearing capacity were obtained based on the field and indoor tests results. The static theory was used to calculate the anti-sliding stability coefficient, anti- overturning stability coefficient and contact stress of the gravity anchorage. The finite element software was used to calculate the horizontal displacement, vertical settlement and contact stress of the gravity anchorage. The calculation results met the relevant requirements, and it can be considered that the gravity anchorage was stable under the tension of main cables. It would provide a reference for the stability study of the gravity anchorage of suspension bridges.

scholarly journals Autonomous main-cable vibration monitoring using wireless smart sensors for large-scale three-pylon suspension bridges: A case study

2018 ◽  
Vol 39 (3) ◽  
pp. 604-615 ◽  
Author(s):  
Huaping Ding ◽  
Qinghong Shen ◽  
Sidan Du
Keyword(s):  
Dynamic Characteristics ◽  
Large Scale ◽  
Stable State ◽  
Vibration Monitoring ◽  
Smart Sensors ◽  
Suspension Bridges ◽  
Main Cable ◽  
Wireless Smart Sensors ◽  
Main Cables

Suspension bridges are supported by main cables that continue beyond the pillars to deck-level supports and must be anchored at each end of the bridge. The dynamic characteristics of the main cables are key indicators used to assess the structural health status of a bridge. In situ real-time health monitoring is an effective way to assess the dynamic characteristics. This paper presents a case study using vibration-based wireless smart sensors deployed on the main cables of a large-scale three-pylon suspension bridge to obtain its dynamic features. The methods of anti-aliasing filtering, statistical analysis and main cable tension force estimation were proposed and embedded into wireless smart sensors to provide autonomous data processing. According to the analysis of the vibration data from the main cables, the results demonstrate that the main cables have been in a stable state over time, and wireless smart sensors are promising for autonomous main-cable monitoring of large-scale three-pylon suspension bridges.

II. On the size of pins for connecting flat links in the chains of suspension bridges

1865 ◽  
Vol 14 ◽  
pp. 139-144 ◽  
Keyword(s):  
Large Scale ◽  
Simple Rule ◽  
Careful Examination ◽  
Suspension Bridges ◽  
Pass Through ◽  
The Right

In the construction of chains of this kind, it is of the highest importance that the pins, which pass through and connect together the links of which the chains are composed, should be of the right size, inasmuch as their being too small, as compared with the links through which they pass, renders ineffective a portion of the iron contained in the latter, which then exists only as a useless load to be carried by such links; while at the same time, if the pins and heads of the links be too large, they become uselessly cumbersome and expensive. Careful examination and experiments made upon a large scale (which will be explained hereafter) have brought out facts by which a simple rule has been arrived at—a rule that may safely be adopted as a guide in deciding upon the relative sizes of these two parts.

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