1. Ph.D. Candidate, Key Laboratory for Bridge and Wind Engineering of Hunan Province, College of Civil Engineering, Hunan Univ., Changsha, Hunan 410082, China.
2. Professor, Key Laboratory for Bridge and Wind Engineering of Hunan Province, College of Civil Engineering, Hunan Univ., Changsha, Hunan 410082, China.
3. Professor, College of Civil Engineering, Hunan Univ. of Science and Technology, Xiangtan, Hunan 411201, China.
4. Professor, Dept. of Mechanical Engineering, Univ. of Houston, Houston, TX 77204 (corresponding author).