Abstract:The implementation premise for seismic ductility mechanism of building structures is that the basic design principles such as "strong column-weak beam" are carried out actually. In previous earthquakes, seismic damage of RC frame structures run counter to the seismic ductility mechanism. In this paper, the experiment and simulation study of the influence of slab and reinforcement on the formation of "strong column-weak beam" mechanism by using effective flange of beam were summarized. Based on SAP2000 software, pushover analysis were carried out on three models of RC frame structures, i.e., structure without floor, structure without floor but considering beam stiffness amplification, and structure with floor by using three lateral loading modes. The relationship curve of force and displacement, the order of plastic hinge, the top displacement, and inter story displacement were analyzed. The results showed that: the phenomenon of "strong column and weak beam" in pure frame structure without floor slab is the most obvious, followed by the model considering the beam stiffness amplification, and that in structure with floor slab is the least obvious. It is proved that the negative moment bearing capacity, stiffness, and other parameters reflecting "strong column and weak beam" and the occurrence order of plastic hinge have obvious corresponding relations with floor slab and in-plate reinforcement. The floor slab and reinforcement, which affect the overall deformation performance and plastic energy dissipation capacity of frame structures, are important influencing factors for the realization of seismic ductility mechanism. In subsequent structural design, it is suggested to consider the actual floor and reinforcement modeling for calculation and analysis.
