1. Department of Civil and Environmental Engineering, University of California, Berkeley, Berkeley, CA 94720-1710, USA.
2. Institute of Intelligent Flexible Mechatronics, Jiangsu University, Zhenjiang 212013, P.R. China.
3. Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Changzhou University, Changzhou 213164, P.R. China.
4. School of Naval Architecture and Civil Engineering, Zhejiang Ocean University, Zhoushan 316000, P.R. China.