1. Lecturer, School of Civil Engineering, Zhengzhou Univ., 100 Kexue Rd., Zhengzhou 450001, China.
2. Graduate Student, School of Civil Engineering, Zhengzhou Univ., 100 Kexue Rd., Zhengzhou 450001, China.
3. Lecturer, Hubei Key Laboratory of Power System Design and Test for Electrical Vehicle & School of Automotive and Traffic Engineering, Hubei Univ. of Arts and Science, 296 Longzhong Rd., Xiangyang 441053, China (corresponding author).