Spiral transitions

Akın, Levent; Şahin, Bayram; Habib, Zulfiqar

doi:10.1007/s11766-018-3554-4

Cited by 5 publications

(4 citation statements)

References 63 publications

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“…Based on this law, the coordinates of the points of the simulated curve are calculated. This is the difference between the proposed approach and those approaches reported in [1][2][3][4][5][6][7][8][9][10][11][12][13][14] that consider the construction of a railroad track's curvilinear sections. In those papers, a curve is constructed, and then the distribution of the curvature and its derivative are determined.…”

Section: Discussion Of Results Of Studying the Geometric Modeling Of ...mentioning

confidence: 99%

“…The spiral section is arranged between two straight rails providing, alas, only for the second order of smoothness. In [3], it is noted that the spiral curves are not characterized by mathematical features and extremes of curvature. They are used to smooth paths in places of abrupt change in curvature where the speed of a moving object increases.…”

Section: Literature Review and Problem Statementmentioning

confidence: 99%

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Devising an approach to the geometric modeling of railroad tracks along curvilinear sections

Borisenko

Ustenko

2022

EEJET

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This paper proposes an approach to arranging curvilinear sections of the railroad track, which involves the replacement of two transitional ones and a circular curve with one curvilinear section. Modeling this section implies the construction of a curve in the plan and profile, the joint consideration of which forms the spatial appearance of the curve, which ensures a smooth transition between the rectilinear rails. The need for such transitions is due to the terrain, the need to bypass settlements, and the presence of geological, geographical, and other obstacles that occur when laying railroads. A curvilinear section is modeled in the plan using a curve that is represented in natural parameterization under the law of curvature distribution in the form of a fifth-power polynomial. At the same time, at the start and end points of the section, the curvature and its derivative accept zero values. The outer rail elevation retraction (modeling in the profile) is performed using the curve built, whose sections are also represented in natural parameterization with the dependences of the curvature distribution on the arc length in the form of fourth-power polynomials. At the docking point of the sections, the third order of smoothness is ensured, which implies the equality of values of the functions, their derivatives, the curvature, and a derivative of the curvature from the length of its natural arc. Measures have been proposed to ensure the predefined track gauge retraction. The application of the proposed approach to model a railroad track along the curvilinear section with a variable-radius curve could make it possible to achieve a favorable curvature distribution, a smooth elevation retraction of the outer rail and the track gauge. That would consequently improve the safety of rolling stock running along the curvilinear section of the track, reduce the lateral and vertical efforts that predetermine the wear of rails and wheelsets.

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Section: Discussion Of Results Of Studying the Geometric Modeling Of ...mentioning

confidence: 99%

Section: Literature Review and Problem Statementmentioning

confidence: 99%

Devising an approach to the geometric modeling of railroad tracks along curvilinear sections

Borisenko

Ustenko

2022

EEJET

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“…In addition to the previous work a state-of-the-art paper has been written with focus on line to circle spiral transition curves in railway, highway, robotics, and computer imaging [62]. Challenges, in railway, highway and robotics, are noted there in the design of curves that fulfill smoothness criteria while also account for limitations in curvature, speed and obstacles, and consider energy and time efficiency.…”

Section: New Transition Curvesmentioning

confidence: 99%

Railway Transition Curves: A Review of the State-of-the-Art and Future Research

Brustad

Dalmo

2020

Infrastructures

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Transition curves are a useful tool for lateral alignment of railway segments. Their design is important to ensure safe and comfortable travel for passengers and cargo. Well designed transition curves can lead to reduced wear of tracks and vehicles, which is beneficial from a maintenance point of view. Extensive studies have been performed through decades to find transition curves that can replace existing railway segments for the purpose of enhancing certain properties. Those studies seek to form curves that satisfy desired evaluation criteria, which are often connected to geometric continuity between the curve segments, and vehicle dynamics, to secure a smooth ride. This research topic is still ongoing and active at present. Recent results and findings are in line with the developments on the topic of vehicle dynamics and within the railway industry. For this reason it is appropriate to collect and discuss the latest work, since there are no up-to-date detailed literature reviews available. This paper explores the present state-of-the-art of railway transition curves, and identifies some of the research challenges and future research opportunities in the field.

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“…Generally, the aim of constructing a spiral curve is to let the curvature and, consequently, the centrifugal force increase gradually. Otherwise, the centrifugal force is instantaneously applied to the vehicle, and the safety of the entering and exiting regions of the curve is affected [5,6]. erefore, the centrifugal force should be controlled by constructing a one-way grade to increase the safety of the curve.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of the Application of Maximum Radius in Horizontal Curves Using Vehicle Dynamic Simulation

Aldeen

Kordani

Hosseinian

et al. 2022

Advances in Civil Engineering

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Most road design standards recommend using a spiral curve for transitions. The main advantages of using this curve are the gradual increase in the centrifugal force, creating a suitable space for presenting superelevation, and providing a correct perception of the curve for the driver. In this research, vehicle dynamic simulation software CarSim and TruckSim is used to assess the forces imposed on the vehicles. In this regard, 360 scenarios are considered for sedans, SUVs, and trucks, which consist of variations of the road geometry (simple or spiral horizontal curve), curve radius, and type and speed of the vehicle. In addition, the regression analysis is performed to examine the relationships between the lateral acceleration (as a dependent variable) and the vehicle speed, curve radius, and vehicle type (as independent variables). The results indicate that in all cases, safety in the spiral horizontal curve is greater than that in the simple horizontal curve, and the maximum side friction factor, lateral acceleration, roll rate, roll angle, yaw rate, and lateral distance in the simple horizontal curve are higher than those in the spiral horizontal curve. Moreover, the difference percentage of the side friction factor, lateral acceleration, yaw rate, and lateral distance between the simple and spiral horizontal curves is the highest in SUVs, followed by sedans and trucks, while the difference percentage of the roll rate and roll angle is the highest in sedans, followed by SUVs and trucks. The results of regression analysis illustrate that the coefficient of determination (R2) in the proposed model is 0.972, 0.964, and 0.981 for sedans, SUVs, and trucks, respectively, indicating the strong relationships between the dependent and the explanatory variables as well as the capability of the model to cover the data.

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Spiral transitions

Cited by 5 publications

References 63 publications

Devising an approach to the geometric modeling of railroad tracks along curvilinear sections

Devising an approach to the geometric modeling of railroad tracks along curvilinear sections

Railway Transition Curves: A Review of the State-of-the-Art and Future Research

Evaluation of the Application of Maximum Radius in Horizontal Curves Using Vehicle Dynamic Simulation

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