Behavior and Design of a Yielding Shear Panel Device for Seismic Risk Mitigation

Description

Earthquakes are one of the deadliest natural disasters, responsible for the loss of thousands of lives each year. Recent research into seismicity has revealed that Hong Kong is exposed to moderate risk, which can have severe consequences in such a highly populated city. However, building codes in Hong Kong do not require consideration of earthquake loadings, and post-disaster buildings such as hospitals and police and fire stations will all be vulnerable. If seismic upgrading is considered to be desirable, then thousands of buildings will require rehabilitation. An effective retrofit strategy, both in terms of mechanical performance and cost, is urgently required.Over the last three decades, the concept of energy dissipation for seismic risk mitigation has gained momentum. Its primary benefit is the reliable absorption of input earthquake energy in specially dedicated elements (i.e., structural fuses or dampers) other than the primary structural frames. These dampers can be arranged in a way that facilitates repair/replacement. Passive dampers rely on certain material characteristics, such as yielding in energy dissipation. This enhances the reliability and affordability of these dampers vis-a-vis active dampers.The PI and the Co-Is recently explored a new steel damper – the Yielding Shear Panel Device (YSPD) – which makes use of the shear yielding of thin steel plates to dissipate energy. Pilot tests have demonstrated very promising performance, with a large amount of energy dissipated by this very light and inexpensive device. However, many factors that influence the damper’s performance are yet to be investigated, such as: (1) the plate slenderness ratio, (2) edge stiffness, (3) connection details, (4) fatigue life, (5) imperfections, and (6) frame-damper interaction. Furthermore, constitutive and fatigue life models need to be developed to conduct a proper seismic analysis of practical structures that incorporate these dampers (as a retrofit or as a new design).A comprehensive study combining both theoretical and experimental investigations will thus be conducted. The outcomes will include:a full assessment of the cyclic behavior of the YSPD;identification of the important parameters that control its effectiveness;design, implementation, and quantification of the energy absorption and fatigue life of the YSPD; andbased on the above studies, a practical design methodology that assist engineers in the implementation of this damper for retrofitting or new seismic design will be proposed.This research will have great local and international significance as an affordable and easy way to implement a seismic upgrade strategy.