عنوان مقاله [English]
The use of concrete shear walls in lateral resistance systems comes with certain disadvantages. Low ductility against lateral loadings due to their high stiffness and low vibration period of these systems can be mentioned as their drawbacks. Inadequate attention to shear capacity of the connecting region of roof and shear wall is also worth noting. These problems can increase the
vulnerability of the structure when subjected to lateral loads. Previous studies have demonstrated the benefits of providing energy dissipation devices to improve structure behavior. Metallic dampers, such as Added Damping and Stiffness (ADAS) and Triangular Added Damping and Stiffness (TADAS), are among the simplest energy dissipating devices that are being used in design of the
new generation of earthquake-resistant structures. Application of such devices in the lateral resistance system of a structure imposes a reduced maximum on internal forces. In this article, a more practical arrangement of yielding metal dampers has been proposed to reduce the base shear of the structure and improve its response and, as a result, diminish the seismic damages caused by earthquakes. The proposed arrangement is designed in a way that can allow the largest displacements and cause the highest energy dissipation.To demonstrate, a numerical example of optimal damper designs with different excitation inputs was presented. Ground acceleration records of the Imperial Valley, Kobe, Loma Prieta, and Northridge earthquakes were used as the disturbing ground motion in a series of numerical simulations of a multi-story steel building. The numerical simulations were carried out using Sap2000 program and the nonlinear dynamic behaviors of the different systems were compared to those of the conventional reinforced concrete shear wall equipped structure. Results indicated that the TADAS devices exhibited excellent energy dissipation and ductility leading to a massive increase in period of the first mode of vibration accompanied with up to 40 percent decline in peak values of base shear and absolute accelerations of the stories.