1. Associate Professor, Dept. of Civil Engineering, Zhejiang Univ., Hangzhou 310027, China; and, Visiting Scholar, Dept. of Civil and Environmental Engineering, Univ. of Illinois at Urbana-Champaign, Urbana, IL 61801.
2. Research Associate Professor, Dept. of Aerospace Engineering, Univ. of Illinois at Urbana-Champaign, Urbana, IL 61801.
3. Ph.D. Candidate, College of Civil Engineering, Hunan Univ., Changsha 410082, China.
4. Nathan M. and Anne M. Newmark Endowed Chair of Civil Engineering, Dept. of Civil and Environmental Engineering, Univ. of Illinois at Urbana-Champaign, Urbana, IL 61801 (corresponding author).
5. Professor, Dept. of Aerospace Engineering, Univ. of Illinois at Urbana-Champaign, Urbana, IL 61801.