Events Calendar

Sonny Astani Department Seminar

Speaker: Prof. Xin Wang, Research Institute of Disaster Science, Tohoku University, Japan

Talk Title: 1D Wave Propagation Analysis and Shear-Wave Velocity Extraction of Super High-Rise Buildings Based on Ambient Vibrations Measurement

Abstract: Shaking modes of super high-rise buildings are very complex. In the first part of this study, three 2-D frame models of super high-rise buildings including bending and shear deflections in each member are used to simulate shear-wave propagation within the building. Different shaking modes at the lower stories of the three models are designed, each with a different mass-and-rigidity distributions, such as: (i) all stories shaking in a shear-bending mode, (ii) the lower eight stories shaking in pure bending mode, and (iii) the fourth to eighth stories shaking in pure bending mode. The wave reflections at the boundaries of stories with different shaking modes are examined from the response waves and the impulse responses with respect to the response of the top. Because of the wave interference, it is difficult to observe the travel path directly from the response waves. However, the travel path and the reflected waves can be observed clearly from impulse responses. For the stories shaking in pure bending mode, similar to the models (ii) and (iii), because there is no inter-story shear deformation, the apparent shear-rigidity of these stories seems infinite, which leads to zero shear-wave travel time and shear-wave velocities cannot be extracted successfully. In the second part of this study, 1D vertical shear-wave propagation in two super high-rise buildings are identified using ambient vibration response recorded by a portable array. The identified shear-wave propagation from the impulse response, including the boundary conditions, is compared with the simulated ones. Attempt is made to identify the shear-wave velocities for the individual stories.

Biography: Dr. Xin Wang is an Assistant Professor of the Research Institute of Disaster Science of Tohoku University in Japan. Her research combines knowledge of seismology and civil engineering and aims to disaster prevention from earthquakes. Her research topics include building damage detection and building damage causes examination due to ground shaking during big earthquake disasters, e.g. the 2008 Wenchuan Earthquake in China, the 2011 Great East Japan Earthquake, and the 2014 Ludian Earthquake in China. She is currently studying damage from the recent 2016 Kumamoto Earthquake in Japan. Her main recent research topics are Structural Health Monitoring of super high-rise buildings, and earthquake response recording systems using smart devices. Native of China, Dr. Wang received her B.S. and M.S. degrees in Civil Engineering from the Dalian Jiaotong University and Southeast University, respectively, after which she moved to Japan and earned her Ph.D. degree from the Aichi Institute of Technology.

Host: Maria Todorovska

Location: Seeley G. Mudd Building (SGM) - 101

Audiences: Everyone Is Invited

Contact: Kaela Berry