Optimization and analysis of hysteretic energy dissipators in reinforced concrete frame structures of five,10 and 15 stories

Abstract

Frame structures are especially affected by earthquakes, due to their low lateral resistance. The use of energy dissipators may be a suitable solution for these structures; however, the effectiveness of these devices is questionable in low-rise buildings. We therefore analyze the behavior of these devices in frame buildings with varying numbers of stories (five, 10 and 15 stories). The use of hysteretic dissipators is found to considerably reduce the displacements of the bare structures, in addition to significantly improving their resistance, although the absolute accelerations are not reduced. Taller, more slender structures require less rigid dissipators with lower yield forces than shorter, more rigid structures. The effectiveness of the dissipators is also demonstrated by increasing the number of stories of the structures. The effectiveness of the dissipators increases as the rigidity of the structure decreases, as observed for the highest frame structures considered in this research, or as also occurs with the characteristics of the seismic records, such as their impulsivity. A high level of rigidity of the structures (as in low-rise structures or those with a significant number of stiffening elements, such as walls or braces) may have a significant impact on the behavior of the dissipators, due to the low displacement of the bare structures, which reduces their effectiveness. Finally, given the complexity of the different designs for dissipators in the scientific literature, this research offers a new, simple way to design dissipators based on the structural characteristics of the bare frames. To carry out this research, a nonlinear static analysis (push-over) and dynamic analysis are carried out using two different characteristic records, as part of a search for the optimal characteristics of the devices and to analyze how each of them affects the structural behavior in buildings with different numbers of stories.