1. Institute of Sound and Vibration Research; Hefei University of Technology; Hefei Anhui 230009 China
2. Department of Civil Engineering; University of Siegen; Siegen D-57068 Germany
3. College of Mechanical and Electrical Engineering; Wenzhou University; Wenzhou 325035 Zhejiang China
4. School of Mathematical Sciences; Dalian University of Technology; Dalian 116024 Liaoning China
5. Department of Modern Mechanics; University of Science and Technology of China; Hefei 230027 Anhui China