1. College of Mechanical-Electronic and Vehicle Engineering, Weifang University, Shandong 261061, China;
2. Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO 80309
3. Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO 80309;
4. College of Mechanical Engineering, Shenyang University of Technology, Liaoning 110870, China
5. School of Aerospace Engineering and Applied Mechanics, Tongji University, Shanghai 200092, China