INTEGRATED DESIGN OF STEEL FRAMES AND ADDED DAMPER USING ENERGY- BASED METHOD

Energy-based methods for structural damage detection have been widely investigated in the last decade. In this paper, the energy balance concept used in these methods is proposed for integrated design of the steel frames equipped with added damper. The proposed procedure is based on the assumption that all of input energy is dissipated by added damper and plastic work done by structural elements (beams and columns). The required damping coefficient and cross sectional area of elements are determined by equating the total dissipated energy (energy capacity) to the input energy (energy demand) such that the target displacement does not exceed maximum displacement and uniform drift is reached. The total dissipated energy (energy capacity) is considered to be the sum of the energy dissipated by added damper and the hysteretic energy damped out by plastic work in structural elements. The proposed method is evaluated by numerical simulations. The method is applied for integrated design of two moment frames with added dampers. In both cases, push over analysis for behavior of the frames indicate that while the structural elements are reduced in size (compared to conventional design), the designed frames with added dampers have a good performance by developing plastic hinges in all beams.