1. Faculty of Infrastructure Engineering, Dalian University of Technology, Dalian 116024, P. R. China
2. Department of Modern Mechanics,University of Science and Technology of China, Hefei 230027, P. R. China
3. State Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics and International, Research Center for Computational Mechanics, Dalian University of Technology, Dalian 116024, P. R. China