PSI - Issue 12

N. Bosso et al. / Procedia Structural Integrity 12 (2018) 330–343 N. Bosso et al. / Structural Integrity Procedia 00 (2018) 000–000

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Fig. 12. Wheel unloading ratio DQ/Q on the detailed wagon in the middle of the train (25 th wagon).

4. Conclusions

The work analyses a long train using the multibody code Simpack. The benefit of the proposed approach consists in the possibility to realize mixed models of the train, with some vehicles modeled using a simplified approach, and some others modeled in detail. The results of this paper show that the strategy adopted for the model allows to investigate the effects on a single vehicle inside a long train reducing the computation effort. Furthermore the results show that the in-train forces are few influenced by curves and the number of d.o.fs used to describe the vehicle composing the train. The results support the model actually used for long train simulation that are usually based on simplified model with one d.o.f. Another important result of this work is that the position of the vehicle inside the composition can have an important role in the dynamic behavior of the vehicle and can modify the critical wheelset or wheel of the wagon. This aspect should be considered during the design of railway vehicles, that are usually based on the simulation of the single vehicle, and particular attention should be paid to the different positions that the vehicle can assume during the train composition. Bosso, N., Zampieri, N., 2017. Long Train Simulation using a Multibody Code. Vehicle System Dynamics 55(4), 552-570. Bosso, N., Gugliotta, A., Zampieri, N., 2012. RTCONTACT: An Efficient Wheel-Rail Contact Algorithm for Real-Time Dynamic Simulations, 2012 Joint Rail Conference. Philadelphia, Pennsylvania, USA, paper JRC2012-74044. Cantone, L., 2011. TrainDy: The New Union Internationale Des Chemins De Fer Software for Freight Train Interoperability. Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit 225 (1), 57-70. Cole, C., 1998. Improvements to wagon connection modelling for longitudinal train simulation, Conference on railway engineering proceedings: engineering innovation for a competitive edge. Rockhampton, Australia. Cole, C., Spiryagin, M., Wu, Q., Sun, Y.Q., 2017. Modelling, Simulation and Applications of Longitudinal Train Dynamics. Vehicle System Dynamics 55(10), 1498-1571. Massa, A., Stronati, L., Aboubakr, A.K., Shabana, A.A., Bosso N., 2012. Numerical Study of the Noninertial Systems: Application to Train Coupler Systems. Nonlinear Dynamics 68(1-2), 215-233. Petrenko, V., 2016. Simulation of Railway Vehicle Dynamics in Universal Mechanism Software. Procedia Engineering 134, 23-29. Qi, Z., Huang, Z., Kong, X., 2012. Simulation of Longitudinal Dynamics of Long Freight Trains in Positioning Operations. Vehicle System Dynamics 50(9), 1409-1433. Spiryagin, M., Wu, Q., Cole, C., 2017. International Benchmarking of Longitudinal Train Dynamics Simulators: Benchmarking Questions. Vehicle System Dynamics 55(4), 450-463. West, L.E., Williams, C.G., Kerr A.J., 1978. A draft gear evaluation project applied to heavy unit train operations, Heavy haul railways conference. Perth, Australia. Wu, Q., Cole, C., Luo, S., Spiryagin, M., 2014. A Review of Dynamics Modelling of Friction Draft Gear. Vehicle System Dynamics 52(6), 733 758. Wu, Q., Spiryagin M., Cole, C., 2015. Advanced Dynamic Modelling for Friction Draft Gears. Vehicle System Dynamics 53(4), 475-492. References