MA Gao1,2,3,CHEN Xiaohuang1
(1. College of Civil Engineering,Hunan University,Changsha 410082,China; 2. Hunan Provincial Key Laboratory on Damage Diagnosis for Engineering Structures (Hunan University),Changsha 410082,China; 3. Hunan Province Engineering Laboratory of Bridge Structure(Changsha University of Science & Technology), Changsha 410076,China)