Structural health monitoring of RC structures under seismic loads has recently attracted much attention in the earthquake engineering research community. In this study, a piezoceramic-based device called ＂smart aggre...Structural health monitoring of RC structures under seismic loads has recently attracted much attention in the earthquake engineering research community. In this study, a piezoceramic-based device called ＂smart aggregate＂ was used for the health monitoring of RC frame structures under earthquake excitations. Three RC moment frames instrumented with smart aggregates were tested using a shaketable with different ground excitation intensities. Distributed piezoceramic- based smart aggregates were embedded in the RC structures and used to monitor their health condition during the tests. The sensitivity and effectiveness of the proposed piezoceramic-based approach were investigated and evaluated by analyzing the measured responses. The displacement ductility demand of the structural members was calculated and compared with the damage index determined from the health monitoring system. The comparison shows that the damage index is compatible with the calculated ductility demand.展开更多
The stress induced martensitic phase transformation of spherical ZrCu nanocrystals embedded in an amorphous matrix was studied in this paper. Microstructural observations revealed that the martensitic transformation o...The stress induced martensitic phase transformation of spherical ZrCu nanocrystals embedded in an amorphous matrix was studied in this paper. Microstructural observations revealed that the martensitic transformation of the nanocrystal was hindered by the surrounding amorphous coating. The existence of two-step transformation from the austenite phase（B2） to the base structure martensite（B19＇） and finally to the most stable superstructure martensite（Cm） was also demonstrated. The Cm martensite with（021） type I twinning symmetrically accommodation was surrounded by the B19＇ martensite with dislocation morphologies.展开更多
基金NSC under Grant No.98-2221-E-027-057-MY2the Center for Research on Earthquake Engineering(NCREE)
文摘Structural health monitoring of RC structures under seismic loads has recently attracted much attention in the earthquake engineering research community. In this study, a piezoceramic-based device called ＂smart aggregate＂ was used for the health monitoring of RC frame structures under earthquake excitations. Three RC moment frames instrumented with smart aggregates were tested using a shaketable with different ground excitation intensities. Distributed piezoceramic- based smart aggregates were embedded in the RC structures and used to monitor their health condition during the tests. The sensitivity and effectiveness of the proposed piezoceramic-based approach were investigated and evaluated by analyzing the measured responses. The displacement ductility demand of the structural members was calculated and compared with the damage index determined from the health monitoring system. The comparison shows that the damage index is compatible with the calculated ductility demand.
基金supported by the National Natural Science Foundation of China (Nos. 51171052 and 51322102)National Basic Research Program of China (973 Projects) (Nos. 2011CB012904 and 2012CB619400)+2 种基金Doctoral Program Foundation of Institutions of Higher Education of China (No. 20112302130006)the Fundamental Research Funds for the Central Universities (HIT. BRET Ⅲ 20120the1)the State Key Lab of Advanced Metals and Materials (2015-Z01)
文摘The stress induced martensitic phase transformation of spherical ZrCu nanocrystals embedded in an amorphous matrix was studied in this paper. Microstructural observations revealed that the martensitic transformation of the nanocrystal was hindered by the surrounding amorphous coating. The existence of two-step transformation from the austenite phase（B2） to the base structure martensite（B19＇） and finally to the most stable superstructure martensite（Cm） was also demonstrated. The Cm martensite with（021） type I twinning symmetrically accommodation was surrounded by the B19＇ martensite with dislocation morphologies.
