1. Key Laboratory of Traffic Safety on Track of Ministry of Education, School of Traffic & Transportation Engineering, Central South University, Changsha 410075, P. R. China
2. Joint International Research Laboratory of Key Technology for Rail Traffic Safety, Central South University, Changsha 410075, P. R. China
3. National & Local Joint Engineering Research Center of Safety Technology for Rail Vehicle, Changsha 410075, P. R. China
4. Department of Aerospace Engineering and Engineering Mechanics, University of Cincinnati, 2851 Woodside Dr, Cincinnati, OH 45221, USA