Passive control methods for seismic response modification

Passive energy dissipation devices have been successfully implemented in buildings around the world to reduce structural response, primarily due to earthquakes, but also for wind and other dynamic loading conditions. The basic objective in using passive energy dissipation devices is to try to concentrate as much of the energy dissipation as possible into specially designed devices, rather than to allow it to develop in the primary structural elements, and thereby to reduce damage in the main structure. Passive approaches differ from active ones in that they do not require any external sources of power to operate, and this is particularly useful in situations such as earthquakes where power is likely to be interrupted when it is most needed. The focus of this paper is a review of passive energy dissipation devices for seismic response modification applications. Past developments and contemporary examples of metallic hysteresis, friction and viscoelastic devices suitable for building applications are included in the first part of the paper. Current design guidelines based on both linear and nonlinear procedures are summarized next. Finally, three recent applications of metallic hysteretic damping devices are described. The first two examples present the use of metallic damping devices as cladding connections, while the third example shows an application of metallic devices in a relatively stiff, unreinforced masonry building. These examples show the potential versatility of passive energy dissipation devices and illustrate some of the analysis methods that might be used.