Three-Dimensional Nonlinear Stability Analysis of Tangent Continuous Welded Rail Track Under Temperature and Mechanical Loads

1997 ◽  
Vol 1584 (1) ◽  
pp. 31-40 ◽  
Author(s):  
Yulin Bao ◽  
Ernest J. Barenberg
Keyword(s):  
Stability Analysis ◽  
Lateral Displacement ◽  
Three Dimensional ◽  
Initial Slope ◽  
Lateral Loads ◽  
Rotational Stiffness ◽  
Geometric Imperfections ◽  
Mechanical Loads ◽  
Lateral Resistance ◽  
Continuous Welded Rail

Results from applications of the three-dimensional continuous welded rail (CWR) track model ILLIBUCKLE to a tangent CWR track with nonlinear resistance and lateral geometric imperfections are presented. Stability analysis is made of the tracks under temperature and mechanical loads by using temperature lateral-displacement curves. Tangent CWR track stability is highly sensitive not only to ballast lateral resistance and geometric imperfections of the the initial track but also to the vertical rotational stiffness in rail-pad fastener systems and vehicle lateral loads. It is concluded that not only the peak values but also the initial slope and the limit resistance in the ballast lateral-resistance curve obtained from a single-tie push test are important in evaluation of track stability. With regard to vertical rotational stiffness in a rail-pad fastener system, track stability is not significantly affected by the nonlinearities, but it is affected by the initial slope. Effects of the combination of mechanical and thermal loads on tangent track stability are presented. The reduction of ballast lateral resistance due to the uplift of rail tie under vehicle vertical loads as well as the magnitude of vehicle lateral loads significantly decrease track stability. A 1400-kg vehicle lateral load can buckle tangent CWR track under a rail-temperature increase as low as 56°C (100°F) under unfavorable conditions.

scholarly journals Methodology for evaluating thermal track buckling in dual gauge tracks with continuous welded rail

2016 ◽  
Vol 231 (3) ◽  
pp. 269-279 ◽  
Author(s):  
Ignacio Villalba ◽  
Ricardo Insa ◽  
Pablo Salvador ◽  
Pablo Martinez
Keyword(s):  
Three Dimensional ◽  
Torsional Stiffness ◽  
Railway Network ◽  
Compressive Stresses ◽  
Freight Traffic ◽  
Lateral Resistance ◽  
Temperature Load ◽  
Continuous Welded Rail ◽  
Linear Behaviour ◽  
New Methodologies

In the National Spanish railway network, two types of track gauge with continuous welded rails are currently in use: the “Iberian” wide gauge (1668 mm) and the standard gauge (1435 mm). In order to improve links and freight traffic between different lines and with the rest of Europe, a dual gauge track with three rails was developed. This solution modifies the classical track configuration, so it is necessary to develop new methodologies and studies to understand its behavior. Among other loads applied on a continuous welded rail track, a considerable rise in temperature induces compressive stresses in the three rails that can lead to lateral track buckling. Moreover, on dual gauge tracks, the addition of the third rail increases the axial compression, which may lead to track instability. For this reason, a three-dimensional continuous welded rail model is developed in this study to be used for dual gauge track buckling analysis on straight tracks subjected to temperature load. The continuous welded rail dual gauge track model consists of beam, solid and spring elements, in which a non-linear behaviour of the ballast is considered. The results obtained may be used to predict the buckling capacity of the continuous welded rail on dual gauge tracks with respect to different parameters such as lateral resistance, lateral imperfections, sleeper spacing or torsional stiffness.

Suggestion for allowable additional compressive stress based on track conditions

2017 ◽  
Vol 232 (5) ◽  
pp. 1309-1325 ◽  
Author(s):  
Kyung-Min Yun ◽  
Beom-Ho Park ◽  
Hyun-Ung Bae ◽  
Nam-Hyoung Lim
Keyword(s):  
Compressive Stress ◽  
Structural Characteristics ◽  
Three Dimensional ◽  
Additional Stress ◽  
Analysis Model ◽  
Temperature Changes ◽  
Lateral Resistance ◽  
Ballasted Track ◽  
Continuous Welded Rail ◽  
Track Bridge

A continuous welded rail has immovable zones due to its structural characteristics. In an immovable zone, thermal expansion and contraction of rails are restricted when the temperature changes, thereby causing excessive axial force on the rail. When the immovable zone of the continuous welded rail is located on a bridge, additional stress and displacement occur through track–bridge interactions. Additional stress and displacement of the rail compared to the embankment area are restricted when constructing the bridge under the continuous welded rail track to prevent problems with the track–bridge interaction according to UIC 774-3R and Euro codes. According to the various codes, the maximum allowable additional compressive stress is 72 MPa, with the conditions of a curve with a radius (R) ≥ 1500 m, UIC 60 continuous welded rail (tensile strength of at least 900 MPa), ballasted track with concrete sleepers and 30 cm of deep for a well-consolidated ballast. However, the lateral resistance that has the greatest effect on track stability can depend on the conditions mentioned above. Therefore, an additional review of various track conditions is required. In this paper, an evaluation of the current criteria was performed using the minimum buckling strength calculation formula, and the allowable additional stress on the rail suggested by codes could only be used on tracks with a large lateral resistance above 18 kN/m/track. Thus, a three-dimensional nonlinear analysis model was developed and analyzed to calculate the allowable additional compressive stress considering various track conditions. According to the results of the analysis, the allowable additional compressive stress was reduced with a comparatively small lateral resistance. The freedom of design can be enhanced with respect to the parameters of various track and bridge conditions using this model.

scholarly journals Determination of Lateral Resistance of Girder-sleeper Fastener for CWR on Ballastless Plate Girder Bridge

2020 ◽  
Vol 20 (1) ◽  
pp. 291-298
Author(s):  
Hyeoung-Deok Lee ◽  
Jong-Keol Song ◽  
Jiho Moon
Keyword(s):  
Lateral Displacement ◽  
Axial Stress ◽  
Ongoing Research ◽  
Railway Bridges ◽  
Lateral Resistance ◽  
Continuous Welded Rail ◽  
Parametric Studies ◽  
Girder Bridge ◽  
Plate Girder

Recently, deteriorated ballastless railway bridges in South Korea have been modified by adding slabs and ballast to improve performance and extend their lifetime. However, this project has been delayed owing to a lack of budget, poor working conditions around the bridge, and the absence of traffic-blocking time. As an alternative, there is ongoing research on the direct installation of a continuous welded rail (CWR) to the bridge using an improved girder-sleeper fastener. To achieve this, the girder-sleeper fastener must have sufficient lateral resistance to prevent track buckling. In this study, to prevent track buckling, an appropriate lateral resistance for the girder-sleeper fastener was proposed by a series of parametric studies based on the additional axial stress of the rail on the bridge specified in the Korean design code. The parameters considered in this study were the span length, track radius, lateral displacement of the plate girder, and lateral resistance of the girder–sleeper fastener.

scholarly journals Lateral Resistance Requirement of Girder-Sleeper Fastener for CWR Track on an Open-Deck Steel Plate Girder Bridge

2021 ◽  
Vol 11 (15) ◽  
pp. 6681
Author(s):  
Hyeoung-Deok Lee ◽  
Sanghyun Choi ◽  
Jiho Moon
Keyword(s):  
Steel Plate ◽  
Lateral Displacement ◽  
Railway Bridge ◽  
Lateral Resistance ◽  
Continuous Welded Rail ◽  
Resistance Criterion ◽  
Girder Bridge ◽  
High Level ◽  
Curve Radius ◽  
Plate Girder

For an open-deck steel plate girder railway bridge with rail joints, frequent damage to the bridge members and a high level of noise and vibration occur. By installing continuous welded rail (CWR) to the bridge, it is possible to reduce the noise and impact force of the bridge. However, current girder–sleeper fasteners have low lateral resistance in nature and track buckling can occur when CWR is used on such a bridge. Therefore, a new girder-sleeper fastener with proper lateral resistance to prevent CWR track buckling is needed. In this study, the lateral resistance requirements of a girder-sleeper fastener are investigated through a series of finite element (FE) analyses and parametric study. The effect of peak lateral resistance of the fastener, curve radius, girder length, and lateral displacement of girder are examined. From the analysis results, the peak lateral resistance criterion of the girder–sleeper fastener is proposed for the design of a new fastener for CWR tracks on an open-deck steel plate girder bridge.

Three-dimensional face stability analysis of shallow tunnels using numerical limit analysis and material point method

2021 ◽  
Vol 112 ◽  
pp. 103904
Author(s):  
Fabricio Fernández ◽  
Jhonatan E.G. Rojas ◽  
Eurípedes A. Vargas ◽  
Raquel Q. Velloso ◽  
Daniel Dias
Keyword(s):  
Stability Analysis ◽  
Limit Analysis ◽  
Three Dimensional ◽  
Material Point Method ◽  
Material Point ◽  
Point Method ◽  
Face Stability ◽  
Shallow Tunnels ◽  
Dimensional Face

scholarly journals Stability analysis and attractor dynamics of three-dimensional dark solitons with localized dissipation

2021 ◽  
Vol 103 (4) ◽  
Author(s):  
Christian Baals ◽  
Alexandre Gil Moreno ◽  
Jian Jiang ◽  
Jens Benary ◽  
Herwig Ott
Keyword(s):  
Stability Analysis ◽  
Three Dimensional ◽  
Dark Solitons ◽  
Attractor Dynamics
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