Experimental assessment of moment resisting rc frames with innovative double-stage steel yielding dampers

Considering the existing building stock of our country, it is understood that the vast majority of existing buildings need to be reinforced against earthquakes. In the current system, this retrofitting process is mostly carried out by demolishing the buildings under the name of "Urban Transformation" and rebuilding them in accordance with current regulations. This process not only increases the value of the buildings but also allows the building owners to live in an earthquake-resistant structure. However, the reconstruction of buildings is both costly and takes a long time. In addition, it is not possible to demolish and rebuild buildings in all cases. For example, buildings with historical value are the most important examples of buildings that cannot be demolished. Such buildings should be made earthquake-resistant with appropriate retrofitting techniques. Another example is the buildings that cannot have the same floor height or total floor area when demolished according to the changing zoning plans. These buildings may be preferred to be retrofitted instead of demolished by the building owners. Another example is workplaces that do not want to interrupt their work. In order to minimize their losses, these workplaces may prefer retrofitting in a shorter period of time instead of demolishing and rebuilding the building. In order to keep public expenditures low, retrofitting methods that are much more cost-effective, especially for schools and other public buildings, are a preferable option. One of the retrofitting methods is the placement of yielding steel dampers between the frames of the structure at appropriate locations. In this application, which is the subject of this thesis, the earthquake forces acting on the structure are reduced by increasing the damping ratio of the structure. The innovative two-stage metallic bending dampers presented in this thesis offer many parameters to adjust the behavior of this type of dampers in the desired way. By adjusting these parameters as needed, different behavior of the damper at different story drift levels can be achieved. In this way, the large energy transferred to the structure during strong ground motions is absorbed by the addition of flexural steel dampers and the damage to the structure is reduced.