1. Ph.D. Candidate, State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan Univ., Changsha, Hunan 410082, P.R. China.
2. Professor, George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332 (corresponding author).
3. Professor, State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan Univ., Changsha, Hunan 410082, P.R. China.