1. Lecturer, National Key Laboratory of Rotorcraft Aeromechanics, College of Aerospace Engineering, Nanjing Univ. of Aeronautics and Astronautics, Nanjing 210016, China.
2. Professor, National Key Laboratory of Rotorcraft Aeromechanics, College of Aerospace Engineering, Nanjing Univ. of Aeronautics and Astronautics, Nanjing 210016, China (corresponding author).
3. Engineer, National Key Laboratory of Rotorcraft Aeromechanics, College of Aerospace Engineering, Nanjing Univ. of Aeronautics and Astronautics, Nanjing 210016, China.