Investigation on the Bogie Pseudo-Hunting Motion of a Reduced-Scale Model Railway Vehicle Running on Double-Curved Rails
In this paper, an experimental and theoretical study on the bogie pseudo-hunting motion of a reduced-scale model railway vehicle, running on double-curved rails, is presented. Since the actual bogie hunting motion, occurring for real railway vehicles running on straight rails at high travelling speeds, cannot be obtained in laboratory conditions, due to the speed and wavelength limitations, a pseudo- hunting motion was induced by employing double-curved rails. Firstly, the test rig and the experimental procedure are described. Then, a geometrical model of the double-curved rails is presented. Based on such model, the variation of the carriage rotation angle relative to the bogies and the working conditions of the yaw damper are clarified. Vibration spectra recorded during vehicle travelling, on straight and double-curved rails, are presented and interpreted based on a simple vibration model of the railway vehicle. Ride comfort of the vehicle is evaluated according to the ISO 2631 standard, and also by using some particular frequency weightings, which account for the discomfort perceived during the reading and writing activities. Results obtained in this work are useful for the adequate design of the yaw dampers, which are used to attenuate the lateral vibration of the train car bodies.
 ISO 2631 Standard, Mechanical Vibration and Shock – Evaluation of Human Exposure to Whole-Body Vibration, 1997, pp. 1–27.
 M. J. Griffin, Handbook of Human Vibration. London: Academic Press, 2003, 2nd ed., ch. 2–12, pp. 27–530.
 O. Thuong, and M. J. Griffin, “The Vibration Discomfort of Standing Persons: 0.5 to 16 Hz Fore – and – Aft, Lateral, and Vertical Vibration,” Journal of Sound and Vibration, 330(4), pp. 816–826, 2011.
 ENV 12299, Railway Applications – Ride Comfort for Passengers, 2010.
 G. Gallais, H. Ohno, and C. Talotte, “Frequency Weightings for the Evaluation of Discomfort of Standing Passengers on Trains,” Proc. of 9th World Congress on Railway Research, pp. 1–12, 2011.
 S. Komamura, R. Watanabe, K. Mizumukai, T. Mizobuchi, Y. Morita, T. Masamura, J. Arai, H. Matsumoto, W. Tsuji, H. Matsuda, A. Kani, Y. Ono, F. Tsuji, and N. Yoshida, Automotive Suspension. Tokyo: Kayaba Technical Publisher, 2005, 2nd ed., pp. 26–68 (in Japanese).
 K. Tanifuji, “The Development of Car Vibration Analyzing System for Maintenance of Riding Quality. 1st Report: Outline of the Vibration Analyzing System,” Trans JSME C, 52(481), pp. 2405–2408, 1986 (in Japanese).
 C. V. Suciu, and T. Tobiishi, “Comfortableness Evaluation of an Automobile Equipped with Colloidal Suspensions,” JSME Journal of System Design and Dynamics, 6(5), pp. 555–567, 2012.
 V. Kumar, and V. H. Saran, “A Review of the Performances of Reading Activity by Seated Subjects Exposed to Whole Body Vibration,” International Journal of Mechanical Engineering and Robotics Research, 1(1), pp. 193–198, 2014.
 C. H. Lewis, and M. J. Griffin, “Prediction the Effects of Vertical Vibration Frequency, Combinations of Frequencies and Viewing Distance on the Reading of Numeric Displays,” Journal of Sound and Vibration, 70(3), pp. 355–377, 1980.
 J. Sundstrom, Difficulties to Read and Write Under Lateral Vibration Exposure. Stockholm: Doctoral Thesis, Royal Institute of Technology Aeronautical and Vehicle Engineering, Rail Vehicles, 2007, pp. 56–58.
 T. Tomioka, T. Takigami, A. Fukuyama, and T. Suzuki, “Prevention of Carbody Vibration of Railway Vehicles Induced by Imbalanced Wheelsets with Displacement Dependent Rubber Bush,” Journal of Mechanical Systems for Transportation and Logistics, 3, pp. 131–142, 2010.
 T. Tomioka, and T. Takigami, “Reduction of Bending Vibration in Railway Vehicle Carbodies using Carbody-Bogie Dynamic Interaction,” Vehicle System Dynamics, 48, pp. 467–486, 2010.
 B. Suciu, and T. Tomioka, “Experimental Investigation on the Elastic and Dissipative Characteristics of a Yaw Colloidal Damper Destined to Carbody Suspension of a Bullet Train,” Journal of Physics: Conference Series, 744(012142), pp. 1–11, 2016.