1. University Lecturer, Hunan Provincial Key Laboratory of Structures for Wind Resistance and Vibration Control and School of Civil Engineering, Hunan Univ. of Science and Technology, Xiangtan, Hunan 411201, China (corresponding author).
2. Associate Professor, College of Civil Engineering, Hunan Univ., Changsha 410082, China.
3. Professor, College of Civil Engineering, Hunan Univ., Changsha 410082, China.