Newly Developed Economic Hysteretic Damper for Effective Seismic Building Protection

Mitigation of structural damages or structural collapse due to seismic events is of major importance to avoid fatalities and grants immediate occupancy after the earthquake. Therefore, new and existing structures are studied if these are adequate to fulfill stability criteria while regional seismic conditions and soil types must be considered. An essential technical tool to achieve stability, better seismic performance and to avoid structural damages is to increase significantly structural inherent damping. An economic and extremely effective way of increasing damping is with hysteretic dampers within wall bracing arrangements of buildings and other facilities, where seismic isolation cannot be applied properly. A newly developed hysteretic device called SHARK® is rather promising, as it can provide reliable energy dissipation over many cycles even during a long earthquake duration and it is still a very economic approach compared to other damper solutions like viscous dampers. This device is consisting of specially shaped serially and parallelly arranged lamellas. The lamella shape is similar to the gills of a shark. This specific shape allows excellent energy dissipation, reliable initial stiffness, is redundant and accepts many movement cycles until device may fail. The entire device consists of one single unit, which is easy to handle and to install into a wall bracing. Inspection is simple and functionality status can be properly checked compared to other systems like BRBs. The SHARK® can be used for retrofitting, too. In a first approach a case study for a regular building structure has been carried out to verify and quantify the efficiency of the device. Then excessive testing of regular and adaptive devices at EUCENTRE in Pavia was performed, to proof reliability and consistency with numerical approach strategy. With the adaptive approach the energy dissipation capacity is strongly depending on seismic intensity and displacement amplitude, what opens new doors for modern but still economic design concepts.