1. School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
2. Engineering Cluster, Singapore Institute of Technology, 10 Dover Drive, Singapore 138683, Singapore
3. International Center for Applied Mechanics, State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an 710049, P. R. China