International benchmarking of longitudinal train dynamics simulators: results

Abstract

This paper presents the results of the International Benchmarking of Longitudinal Train Dynamics Simulators which involved participation of nine simulators (TABLDSS, UM, CRE-LTS, TDEAS, PoliTo, TsDyn, CARS, BODYSIM and VOCO) from six countries. Longitudinal train dynamics results and computing time of four simulation cases are presented and compared. The results show that all simulators had basic agreement in simulations of locomotive forces, resistance forces and track gradients. The major differences among different simulators lie in the draft gear models. TABLDSS, UM, CRE-LTS, TDEAS, TsDyn and CARS had general agreement in terms of the in-train forces; minor differences exist as reflections of draft gear model variations. In-train force oscillations were observed in VOCO due to the introduction of wheelâ\u80\u93rail contact. In-train force instabilities were sometimes observed in PoliTo and BODYSIM due to the velocity controlled transitional characteristics which could have generated unreasonable transitional stiffness. Regarding computing time per train operational second, the following list is in order of increasing computing speed: VOCO, TsDyn, PoliTO, CARS, BODYSIM, UM, TDEAS, CRE-LTS and TABLDSS (fastest); all simulators except VOCO, TsDyn and PoliTo achieved faster speeds than real-time simulations. Similarly, regarding computing time per integration step, the computing speeds in order are: CRE-LTS, VOCO, CARS, TsDyn, UM, TABLDSS and TDEAS (fastest)

A Modeling Method for the Driving Process of Heavy-Haul Train Based on Multi-Mass Model

“…Figure 7 shows that the experimental results of several dynamic simulators with better effects in the 9 mechanisms are mostly concentrated at 350 kN, and the pull force is approximately 540 kN. In the simulation result of our method, the maximum hook force is 350 kN, and the pull force is 530 kN, which are very similar to the experimental results with better values in the paper [44]. The TANLDSS simulation curve at the bottom of Figure 8 is the actual simulation curve of the TANLDSS mechanism.…”

“…After we established the dynamic longitudinal dynamics model and decoupling device model of the train operation process, according to the conditions and control requirements of the international benchmark tests of heavy-haul train longitudinal dynamics simulators of nine international authoritative organizations in the literature [43][44] of the University of Central Queensland, Spiryagi et al, the corresponding simulation tests are performed in this paper. The results of the maximum coupling force of 9 mechanisms in Spiryagi's paper [44] are shown in Figure 7. The results of the simulated maximum coupling force in this paper are shown in Figure 8.…”

Influence of Draft Gear Modeling on Dynamics Simulation for Heavy-Haul Train

“…Recently, the international benchmarking of longitudinal train dynamics simulators evaluated nine longitudinal dynamics simulation software from six countries [16]. Results show that all software simulations of locomotive traction/ braking force, train resistance, and track gradient are basically the same, while the main difference lies in the use of the draft gear model, which leads to subtle differences in the simulation results of the longitudinal forces, but in general, similar longitudinal force results can be obtained.…”

A Model of Control Valve for Wagons Equipped by k-Blocks

“…LTD studies are carried on not only by Research Centres and Universities but also by Railway Undertakings, in order to develop longer and heavier freight trains. Reference [5] provides an excellent review of this matter and in [6] there is a benchmark of several LTD simulators coming from all over the world. Of course, such studies require a statistic approach [7], as requested by UIC CODE 421 [8] for freight trains interoperability and, among the papers in literature that cover this topic, we can mention here [9] and [10].…”