Thursday, October 5, 2017
11:00 am

Mechanical and Civil Engineering Seminar

"Building monitoring for damage evaluation using seismic waves and deconvolution interferometry"
Norimitsu Nakata, Professor, University of Oklahoma

With a simple one-dimensional model of buildings and deconvolution techniques, we can extract seismic response of the buildings, which are useful for health monitoring.  The deconvolution signals can be interpreted in the time domain (interferometry) or frequency domain (transfer function), and this method allows us to numerically isolate the building response from the soil/subsurface structure.  The response is related to the elastic stiffness, seismic velocities, and attenuation of the building. I apply this method to earthquakes and ambient vibration recorded in different buildings. The response varies depending on the history of strong motion, size of earthquakes to measure, and weather conditions. I also find that due to the 2011 Tohoku earthquake in Japan, seismic velocity at a building in Tokyo (about 400 km far from the epicenter) significantly decreased as about 20%.

Contact Sonya Lincoln lincolns@caltech.edu at 626-395-3385
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