1. School of Mechanical, Industrial & Aeronautical Engineering, University of the Witwatersrand, Johannesburg 2000, South Africa
2. School of Mechanical Systems Engineering, Chonnam National University, Gwangju 61186, South Korea
3. State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing, Jiangsu 210016, China
4. College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, Jiangsu 210016, China