Description:

This seminar will present work on the modal identification of a primary-secondary structure using measured ambient vibration data. The instrumented structure is the Mong-Man-Wai Building, a seven-storied reinforced concrete building situated on the campus of City University of Hong Kong. On its roof a two-storied steel frame has been recently constructed to host a new wind tunnel facility. From a structural dynamics point of view the roof frame and the main building form a primary-secondary structure. The dynamic characteristics of the resulting system are of interest. An array of triaxial acceleration measurement under ambient condition was obtained from the structure. A number of setups were carried out to cover all locations of interest using a limited number of sensors. Modal identification was performed using a Bayesian FFT approach. The mode shapes of the overall structural system were obtained by assembling those from individual setups based on a least-square approach. The identification results reveal a number of interesting features about the structural system.

Biography:

Mr. Fengliang Zhang is a PhD student in Department of Building and Construction, City University of Hong Kong, under the supervision of Dr Siu-kui Au. His research focuses on ambient modal identification using a Bayesian approach and structural vibration field testing.