Track Structure Modeling With Nucars™ and Its Validatation

Elkins, J A; Brickle, Barrie; Wilson, Nick; Singh, Satya Prakash; Wu, Huimin

doi:10.1080/00423114.2002.11666251

Cited by 6 publications

(5 citation statements)

References 1 publication

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“…The primary reason for the development of the new w/r penetration algorithm was to resolve integration instability problems originally encountered with TTCI's multi-body track model for NUCARS [3]. As noted, the integration instabilities had limited the applications of the NUCARS track model mostly to straight track simulations.…”

Section: Nucars Track Modelmentioning

confidence: 97%

“…The Transportation Technology Center, Inc. (TTCI), Pueblo, Colorado, has been developing a real-time w/r contact model for use in the NUCARS vehicle/track interaction multi-body simulation program [3]. The purpose of this development is to extend the simulation capability of NUCARS to include the complicated modeling of vehicles and tracks, such as flexible tracks, rail rotations, and profile variations along the track.…”

Section: Introductionmentioning

confidence: 99%

“…This includes a method for varying rail profile shape along the track. The penetration contact model and flexible track model have been validated through comparisons with the benchmark results of other simulation packages [4] and test results [3]. These models are currently in use for the research and analysis of special track work by TTCI and are expected to be made available to all NUCARS users in 2006.…”

Section: Introductionmentioning

confidence: 99%

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Development of a real-time wheel/rail contact model in NUCARS^®¹and application to diamond crossing and turnout design simulations

Shu¹,

Wilson²,

Sasaoka³

et al. 2006

Vehicle System Dynamics

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A new, stable, multi-point penetration wheel/rail (w/r) contact algorithm has been developed for the NUCARS ® vehicle/track interaction multi-body simulation program. This algorithm resolves previous problems with integration instabilities during wheel flange contact. Contact geometry comparisons using both the standard rigid and new penetration contact models show that the new penetration model correctly calculates the constrained contact geometry for a range of wheel diameters and contact angles. The critical conditions for multiple solutions for w/r profile combinations with steep flanges and the methodologies to account for this problem in NUCARS are also discussed.Applications of the new w/r contact algorithm to diamond crossing and turnout design simulations are presented and compared with test data. These results show that the revised real-time w/r penetration contact model and the flexible track model with rail profile variation capability in NUCARS provide a promising tool for the advanced analysis of special track work.

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Section: Nucars Track Modelmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Development of a real-time wheel/rail contact model in NUCARS^®¹and application to diamond crossing and turnout design simulations

Shu¹,

Wilson²,

Sasaoka³

et al. 2006

Vehicle System Dynamics

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“…NUCARS is capable of predicting the dynamic behavior of almost any rail vehicle, including locomotives and passenger, transit, and freight cars, on virtually any track, including turnouts and detailed track structures. NUCARS software has been benchmarked against other multibody vehicle dynamics programs (11,12) and validated in numerous studies (13)(14)(15)(16)(17). NUCARS models may be defined by using any number of bodies, degrees of freedom, and con-nection elements to describe a vehicle and track system.…”

Section: Nucars Vehicle-track Interaction Modelmentioning

confidence: 99%

Dynamic Vehicle–Track Model to Study the Effects of Track Geometry and Vehicle–Track Interaction on Concrete Tie Rail Seat Load Environment

McHenry¹,

Klopp²,

Thompson

2016

Transportation Research Record: Journal of the Transportation R

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Rail seat deterioration (RSD) of concrete ties is manifested by the loss of concrete material in the rail seat area supporting the rail. This failure mode can lead to track that performs poorly and, in extreme cases, can result in the loss of rail clip hold down, reverse rail cant, and rail rollover derailments. This paper describes the use of a multibody vehicle–track dynamics model developed to study the load environment of concrete tie rail seats, specifically addressing the failure mode of RSD. Vehicle–track interaction simulations were conducted to determine the effect of track geometry perturbations on the overall load environment. Various types and magnitudes of track geometry perturbations, including combinations of surface (vertical) and alignment (lateral) perturbations were considered. Fastening system parameters such as clip hold-down force, tie pad stiffness, and broken insulator conditions were also considered. Results of these simulations suggest that concrete crushing, a hypothesized mechanism of RSD, is unlikely in realistic revenue service conditions. Under the load environments considered, the results augment support for an abrasion-related mechanism of RSD that may be more dependent on tonnage and infiltration of fine particles in the rail seat, two factors not addressed in this model. Results from in-track testing are also presented to compare model outputs with measured in-track forces under artificial track geometry perturbations installed at the Transportation Technology Center’s Facility for Accelerated Service Testing. More broadly, the use of this model to explore the effects of vehicle track interaction on tie and fastener load environment is also discussed.

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“…taking into account every individual sleeper and rail fixing system as opposed to considering them as an homogenous continuum, have also been developed within MBS commercial software in the past few years [11]. This means that the range of application of typical vehicle MBS tools has been extended to the study of rather more local track geometry aspects and discontinuities, integrating the complete vehicle-track system into one modelling environment.…”

Section: Latest Development and Introduction Of 'Discrete' Flexible Tmentioning

confidence: 99%

An investigation of sleeper voids using a flexible track model integrated with railway multi-body dynamics

Bezin

Iwnicki

Cavalletti³

et al. 2009

Proceedings of the Institution of Mechanical Engineers, Part F:

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This article describes a flexible track system model (FTSM) that represents the track structure for a typical ballasted track, taking into account the flexibility of the rails, the sleeper mass and the resilience of the pad/fastening elements, as well as the ballast support stiffness condition. The detailed track model is integrated into a commercial railway vehicle dynamics software, thus allowing for any vehicle to be simulated onto the flexible track while at the same time taking into account the detailed calculation of the non-linear wheel-rail contact interaction. As an example, the application of the FTSM to the study of hanging sleepers, with respect to the UK Railway Group Standard limits, is presented. This example shows the impact of forces because of hanging sleepers on the vehicle and on the track, and attempts at quantifying the damage made to the track components for the specific conditions simulated.

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Track Structure Modeling With Nucars™ and Its Validatation

Cited by 6 publications

References 1 publication

Development of a real-time wheel/rail contact model in NUCARS^®¹and application to diamond crossing and turnout design simulations

Development of a real-time wheel/rail contact model in NUCARS^®¹and application to diamond crossing and turnout design simulations

Dynamic Vehicle–Track Model to Study the Effects of Track Geometry and Vehicle–Track Interaction on Concrete Tie Rail Seat Load Environment

An investigation of sleeper voids using a flexible track model integrated with railway multi-body dynamics

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Track Structure Modeling With Nucars™ and Its Validatation

Cited by 6 publications

References 1 publication

Development of a real-time wheel/rail contact model in NUCARS®1and application to diamond crossing and turnout design simulations

Development of a real-time wheel/rail contact model in NUCARS®1and application to diamond crossing and turnout design simulations

Dynamic Vehicle–Track Model to Study the Effects of Track Geometry and Vehicle–Track Interaction on Concrete Tie Rail Seat Load Environment

An investigation of sleeper voids using a flexible track model integrated with railway multi-body dynamics

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Development of a real-time wheel/rail contact model in NUCARS^®¹and application to diamond crossing and turnout design simulations

Development of a real-time wheel/rail contact model in NUCARS^®¹and application to diamond crossing and turnout design simulations