A Multibody Dynamics Approach to Friction Wedge Modeling for Freight Train Suspensions

Steets, J.; Chan, Brendan J.; Sandu, Corina

doi:10.1115/jrc/ice2007-40050

Cited by 6 publications

(3 citation statements)

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“…The virtual test is one of the two main methods commonly employed in studies related to braking performance and wheel lock-up of a vehicle, with the other method being an actual experimental test (Steets, Chan, Sandu, & Ballew, 2010). Evidently, the instrumentation process in the prototype vehicle to carry out the actual tests and obtain the related output signals consumes a lot of time and cost.…”

Section: Methodsmentioning

confidence: 99%

Heavy Vehicle Multi-Body Dynamic Simulations to Estimate Skidding Distance

Zamzamzadeh

Saifizul

Ramli

et al. 2018

The Baltic Journal of Road and Bridge Engineering

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Abstract. The skid mark is valuable for accident reconstruction as it provides information about the braking behaviour drivers and the speed of heavy vehicles. However, despite its importance, there is currently no mathematical model available to estimate skidding distance (SD) as a function of vehicle characteristics and road conditions. This paper attempts to develop a non-linear regression model that is capable of reliably predicting the skidding distance of heavy vehicles under various road conditions and vehicle characteristics. To develop the regression model, huge data sets were derived from complex heavy vehicle multi-body dynamic simulation. An emergency braking simulation was conducted to examine the skidding distance of a heavy vehicle model subject to various Gross Vehicle Weight (GVW) and vehicle speeds, as well as the coefficient of friction of the road under wet and dry conditions. The results suggested that the skidding distance is significantly affected by Gross Vehicle Weight, speeds, and coefficient of friction of the road. The improved non-linear regression model provides a better prediction of the skidding distance than that of the conventional approach thus suitable to be employed as an alternative model for skidding distance of heavy vehicles in accident reconstruction.

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Section: Methodsmentioning

confidence: 99%

Heavy Vehicle Multi-Body Dynamic Simulations to Estimate Skidding Distance

Zamzamzadeh

Saifizul

Ramli

et al. 2018

The Baltic Journal of Road and Bridge Engineering

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“…These models [2,3,4,5,6] were used primarily to investigate bounce inputs with no warp, or with a constant bolster yaw angle. The research presented in this thesis is a continuation of the prior work done at the RTL.…”

Section: Discussionmentioning

confidence: 99%

“…The quarter-truck model was created with both variably damped and constantly damped geometry. Figure 2 shows the quarter-truck models developed in the RTL at Virginia Tech [2]. The stand-alone model was later expanded to a half-truck model, which incorporated a sideframe, control coils, half of a bolster, and two friction wedges.…”

Section: Previous Workmentioning

confidence: 99%

Complex Bogie Modeling Incorporating Advanced Friction Wedge Components

Sperry

Sandu

Ballew

2009

2009 Joint Rail Conference

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The design of the freight train truck has gone relatively unchanged over the past 150years. There has been relatively little change to the fundamental railway truck design because of the challenges of implementing a cost effective and reliable modification to designs that have proven effective in decades of operation. A common U. S. railway truck consists of two sideframes, a bolster, two spring nests, and four friction wedges. The two sideframes sit on the axels. The bolster rides on springs on top of the sideframes. The friction wedges also ride on springs on top of the sideframe, and are positioned between the bolster and sideframe, acting as a damping mechanism. Better understanding the dynamic behavior and forces on the bodies are critical in reducing unnecessary wear on the components, along with potential negative behavior such as loss of productivity and increase in operating costs. This thesis will investigate the dynamic behavior of the truck under warping conditions using a stand-alone model created in Virtual.Lab. This research covers two main areas.First, the full-truck model will be developed and its simulation results will be compared to test data from the Transportation Technology Center, Inc. (TTCI). Data was provided from warp testing performed at the TTCI facilities in the spring of 2008. Once validated, the model will be used to gain a better understanding of the forces and moments that are propagated through the system, and of the dynamics of all bodies. Due to costs and physical constraints, not every bogie component can be instrumented during test, so the computer model will be able to provide valuable information not easily obtained otherwise.iii Second, full-truck models using different contact geometry between the wedges, sideframes, and bolster will be compared. A model with extremely worn sideframes will allow for investigation into the effects of wear on the damping abilities and warp stiffness of the truck. Another model using split wedges will be compared with the previous model to investigate into the behavior differences in the truck using different types of wedges. By understanding the impact of different geometries on the overall performance of the truck, better decisions on design and maintenance can be made in the future.After creating the models, we found that the full-truck model created in LMS® Virtual.Lab compared well with the test data collected by TTCI. In the comparison with NUCARS® we determined that the stand-alone model, which incorporates the wedges as bodies, captures the warp dynamics of the truck better than NUCARS®, which models the wedges as connections. By creating a model with severely worn sideframes, we were able to determine that the truck loses its abilities to damp bounce in the system as well as to prevent warping when the components become sufficiently worn. The split-wedge model behaved similarly to the standard full-truck model for bounce inputs, but had a significantly different behavior in warp. Further development will be needed on the s...

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