Date, time & venue
2019-06-17;9:00am to 12:00 noon;Room Y305, PolyU
(Supported by Structural Division)
Engineering structures are very critical to sustainable economy. Hence, structures located in seismic regions are required to have seismic design. Seismic isolation systems for engineering structures currently under development employ high-damping rubber bearings, lead rubber bearings, or friction pendulum bearings. These systems are effective in reducing the damaging effects of the horizontal components of an earthquake, but they are not well suited for protection against the vertical components of seismic loads. Current seismic isolation systems also cause large relative horizontal displacement between the foundation and the supported structure, which occurs during a seismic event, further complicating the design. A gap, sometimes called a moat, is usually provided between the isolated structure and the surrounding non-isolated structures to avoid hammering. The need for a moat, however, requires very careful design detail to avoid any rigid connection between the isolated and non-isolated portions of the structure throughout its lifetime. A design that eliminates the need for such design restrictions would be very attractive.
This lecture will present an attempt to overcome the disadvantages existing in current seismic isolation systems by developing innovative periodic metamaterial-based seismic base isolators. These periodic metamaterial-based seismic base isolators, in effect, use the foundation of the structure as the base isolation system. The foundation is made of a new material, called periodic metamaterial, which can block, or reflect, the damaging seismic motion being transmitted to the structure. Both the analytical and experimental studies have performed to demonstrate the feasibility and effectiveness of the proposed periodic metamaterial-based seismic base isolators. Guided by solid state physics, the periodic metamaterial-based seismic base isolators can be made by the periodic metamaterial to exhibit special characteristics that are useful in resisting the loads imposed on structures from earthquakes. Possessing distinct frequency band gaps, this periodic metamaterial will block, or reflect, the incoming seismic motion with the frequencies falling between these gaps. The frequency band gaps in the x, y, and z directions can be controlled by their design and manufacturing, exactly what is needed for periodic metamaterial-based seismic base isolators. One can properly design the frequency band gaps to match the fundamental frequency of the structure, so that its dynamic response will not be amplified; alternatively, one can design the frequency band gaps to match the strong energy frequency components of the design earthquake. Periodic metamaterial-based seismic base isolators have been proposed for engineering structures to mitigate the potential damage caused by the earthquake and to increase the safety margin of the engineering structures. Also, periodic metamaterial-based seismic base isolators can enhance the design of standard engineering structures, which can be licensed and built at lower costs.
Dr. Y.L. Mo, F.ASCE, F.ACI and F.Humboldt, is John and Rebecca Moores Professor at the Civil and Environmental Engineering Department, University of Houston (UH), Houston, Texas. He is also Tsinghua Chair Professor, Institute of Future City and Infrastructure, Tsinghua University, Beijing, China. Dr. Mo’s technical interests are multi-resolution analytical simulations, network analysis, large-scale concrete structure testing and field investigations of the response of structural systems, on which he has more than 400 research publications, including 209 refereed journal papers, many conference, keynote and prestige lectures, research reports, books and book chapters, magazine articles and earthquake field mission reports. Dr. Mo has successfully supervised six post-doc, 25 PhD and over 46 Masters Theses as well as 31 visiting scholar studies. It is also worth noting that with the novel idea presented in this seminar Dr. Mo and his PhD students have obtained two U.S. patents on vibration isolation of structural systems.
This seminar is recommended for HALF CPD day. An attendance certificate will be issued.
The registration fee includes a copy of lecture note
Regular Registration: HK$ 500 each for HKISC/ HKIE Members; HK$ 600 each for non HKISC/ HKIE Members.
Group Registration: HK$ 500 each for group registration of at least 5 people
Please follow the 2 steps registration procedure:
- Fax the completed registration form to Ms. Carol Deng for preliminary registration.
- Post the completed registration form together with a crossed cheque payable to Hong Kong Institute of Steel Construction Limited , Ms. Carol Deng, The Hong Kong Institute of Steel Construction, c/o Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hunghom, Kowloon, Hong Kong. on or before 5th June 2019