1. Department of Astronautical Science and Mechanics Harbin Institute of Technology (HIT) P.O. Box 301, No. 92 West Dazhi Street Harbin 150001 P. R. China
2. Center for Composite Materials and Structures Harbin Institute of Technology (HIT) P.O. Box 3011, No. 2 Yikuang Street Harbin 150080 P. R. China