STRENGTH BALANCE OF STEEL DAMPER COLUMNS AND SURROUNDING BEAMS IN REINFORCED CONCRETE FRAMES

In earthquake-prone countries, energy dissipated devices (dampers) have recently been widely used in building structures. Their main purpose is to mitigate damage to beams and columns during strong seismic events. The dampers act as energy absorbing members. In this study, the strength balance of steel damper columns and surrounding beams contained in reinforced concrete frames is investigated. First, the damper column strength ratio is defined on the basis of the rigid-perfectly plastic mechanical model. Next, a nonlinear dynamic analysis of various frame models was performed to investigate the influence of the damper column strength ratio on the nonlinear seismic response of reinforced concrete frames containing steel damper columns. The results of the analysis indicate that that the proper strength balance of the steel damper columns and surrounding beams is important in maximizing the energy dissipation into the damper columns. The beam-end section connected to the damper columns needs sufficient strength to avoid premature yielding prior to any energy dissipation. To discuss the strength balance of steel damper columns and surrounding beams, the damper column strength ratio is a possible index.