1. Key Laboratory of Traffic Safety on Track, 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, Central South University, Changsha 410075, P. R. China
4. College of Mechanical and Vehicle Engineering, Hunan University, Changsha 410082, Hunan, P. R. China