1. Department of Mechanical Engineering, College of Engineering City University of Hong Kong, Kowloon Tong, Kowloon Hong Kong SAR P. R. China
2. Department of Engineering Mechanics Zhejiang University Hangzhou 310027 P. R. China
3. Department of Material Science and Engineering, College of Engineering City University of Hong Kong, Kowloon Tong, Kowloon Hong Kong SAR P. R. China