Damping Performance Experiment and Damage Analysis of Replacement Connection With Low-Yield-Point Steel

Abstract

The performance design for traditional steel rigid connection cannot fulfill the desired seismic requirements. Though beamcolumn connection with weaken beam end can approximately realize the concept about "strong column -weak beam", the local buckling and the distortion buckling in the weaken zone and the total lateral damage maybe occur in rare earthquake and the capacity is not enough. The replacement connection with low-yield-point steel (LYPS) is proposed base on the idea of resilient structure, and its weakened parts in the flange slab and web plate are filled with LYPS. During earthquake, the LYPS primarily yields and fully dissipates energy. The damage of the main parts in the connection is minor and the LYPS can be replaced after the earthquake. According to the insufficiency of the traditional damage models, the damage model based on differential ratio of elastic plastic dissipated energy is proposed. Low cycle loading experimental research is carried out on three kinds of beam-column connections, which involve the classic connection, the beam end weaken connection and the replacement connection. Comprehensive assessments of damping performanc e are proposed through a variety of performance evaluation parameters. It is approved that the replacement connection has much more excellent bearing capacity, ductility and energy consumption ability. In addition, the proposed energy damage index can repr esent damage evolution process and damage law.