1. Associate Professor, Dept. of Aeronautical Structure Engineering, School of Aeronautics, Northwestern Polytechnical Univ., Xi’an 710072, China (corresponding author).
2. Postgraduate, Dept. of Aeronautical Structure Engineering, School of Aeronautics, Northwestern Polytechnical Univ., Xi’an 710072, China.
3. Engineer, Commercial Aircraft Corporation of China, Ltd., 25 Zhangyang Rd., Shanghai 200120, China.