Equal-displacement principle-based direct seismic-design method for single-yielding precast-concrete frame

Abstract

This study aims to improve the seismic performance and reduce damage of a structure using energy-dissipation connectors, while avoiding the design difficulties of existing methods. In this study, a single-yielding–precast-concrete (SYPC) frame was proposed to realize the design of a controllable bending moment at the beam end. An equal-displacement principle-based direct seismic-design method was proposed for the SYPC frame. First, using a dynamic time–history analysis, the key parameters affecting the stiffness of the frame and the adjustment strategy were explored. Subsequently, based on the equal-displacement principle, the seismic intensity control and target interstory drift were directly determined. Finally, a direct seismic-design method for the SYPC frame based on the equal-displacement principle was proposed. A six-story SYPC frame was designed according to the proposed design method. An elastic–plastic dynamic time–history analysis was performed for the designed frame to verify the effectiveness and accuracy of the proposed design method. The results show that the equal-displacement principle can rapidly and accurately determine the target elastic–plastic displacement of the underground motions of the structure and effectively avoid the iterative solution of structural plastic characteristic parameters, such as equivalent damping and ductility coefficient, encountered in traditional design methods. The proposed design method not only effectively controls the deformation pattern of the structure but also realizes an ideal beam-hinge mechanism. Additionally, by controlling the length and section area of the replaceable energy-dissipating connectors (REDCS) to satisfy the ductility requirement, the stiffness was verified to satisfy the requirements of the frame deformation mechanism.