Mitigation Strategies for Systems Subjected to Vibratory, Shock and Seismic Loads

Worldwide, society has made a tremendous investment in constructed infrastructure, such as buildings and bridges. While the fraction of infrastructure vulnerable to large-scale earthquakes tends to be localized by geography (e.g., the Pacific Rim), there is ample evidence for widespread vulnerability. This strongly suggests the need to develop effective strategies to protect not only new construction but also existing structures likely to be subjected to damaging earthquakes. While various passive, semi-active and active methods for mitigating the effects of earthquakes have been designed for and in some cases applied to large scale structures, none has been shown to be simple, inexpensive, and widely applicable. We now examine the application of TET to the seismic protection of frame structures, in response to this need for a fully passive isolation strategy, lightweight and inexpensive but capable of high performance over a wide range of earthquakes of different properties.