We do not strengthen the building, we weaken the earthquake.
Our anti-seismic device that has been developed as a result of years of research at Bogazici University, Turkey, has very effective energy dissipation capacity due to its unique ability to amplify imposed seismic displacements. Hence, the dynamic characteristics and the load transfer scheme of the existing load bearing system is not altered as a result of seismic retrofit strategy. In other words, the building is not strengthened, but the earthquake is weakened.
Compact Design and Flexible Applicability in Industrial and Residential Buildings
Industrial Buildings
The dampers, with their compact design, are placed at locations at which seismic displacement demands are maximum. This way, the anti-seismic solution does not occupy space and does not prevent functionality and operation of the industrial process.
Residential Buildings
The dampers can alternatively be used in combination with precast post-tensioned vertical walls, taking advantage of the unique gap-opening mechanism that occurs in such structural members. The imposed displacements are hence amplified and a very efficient energy dissipation is obtained. In addition, due to the elastic design of post-tensioning tendons, the system 're-centers' itself and residual displacements (damage) are dramatically reduced.
Comprehensive R&D Studies
Our innovative and unique anti-seismic device has been developed as a result of years of studies at Bogazici University, in which comprehensive literature survey has been made regarding friction-based seismic dampers and the need of the building industry is identified. Cyclic tests in accordance with FEMA-356 regulations have been conducted in Bogazici University Structures Laboratory and an advanced nonlinear analytical model has been developed based on the experiment results. The superior performance of the damper device itself along with the significant improvement it provides in overall seismic performance of buildings have been demonstrated in publications in prestigious international Structural and Earthquake Engineering journals. Furthermore, a pHD thesis has been published.
Experimental Studies
International Publications
The Uniqueness of the Damper
Our damper consists of steel plates, friction disks that are placed at joints that connect these plates and the frictional torque that is obtained by applying torque to the ends of the bolts at these joints. The unique aspects of the damper are as follows:
- Energy dissipation capacity of friction-based dampers is dramatically related to load-displacement (Fz-Δz) relation of the device. In the simulation below, as the angle θi decreases, the damper amplifies the displacements (Δz) imposed on it, hence exhibiting large energy dissipation capacity. (In the simulation you can modify the angle with clicking on the scroller and observe the change in load-displacement (Fz-Δz) curve as the angle changes)
- In similar dampers, frictional torque is only applied at the middle joint. In our damper, frictional torque is applied at all joints, hence further increasing seismic energy dissipation capacity.
Application Fields of The Damper
- Reducing seismic effects on new buildings, hence reducing the material used, providing more architectural space and flexibility, and further reduce seismic effects by providing lighter structure,
- Reducing seismic effects on existing buildings that do not satisfy requirement seismic performance levels
- Providing easy-to-mount dry moment-resisting connections in precast concrete.
Design Support
Our damper, due to its kinematic aspects, has a nonlinear load-displacement relationship. For this reason, the damper is not a brochure-based product that is produced according to a target load capacity. Since the behaviour of the damper is dramatically dependant on the geometrical composition, it is necessary to model and analyze the damper using advanced nonlinear time-history analysis techniques. At KULTECH, we provide full-package structural and earthquake engineering services, that includes non-linear behaviour modelling of all structural members, selection and scaling of required number of relevant strong ground motion records, and fully-detailed performance evaluation of both the structure and the damper. Our damper is designed according to the results obtained from these advanced analyses.