Research On "strong Column Weak Beam" Yield Mechanism Factors Of Reiforced Concrete Frame Structure

In 2008 Wen Chuan earthquake, plastic hinges may occur at the ends of the columns of reinforced concrete frame structure. This kind of phenomenon shows that the strong column weak beam yield mechanism which is required by the current code is not realized. The main reasons are the effects of Cast-in-site floor, the bigger limit value of the axial compressive ratio and the influence of rigid connected fill walls and so on. In this paper, the main influence factors of the strong columns weak beam yield mechanism are analyzed. Given some reasonable suggestions to improve current standard, main contents as follows:(1) Analyze the effects of Cast-in-site floor to strong column weak beam yield mechanism. Make static nonlinear analysis using different models to determine the influence degree of cast-in-site slab to strong column weak beam yield mechanism. Those models include non-slab model, cast-in-site slab model and considering different effective flange width models.(2) Analyze the effects of the limit value of the axial compressive ratio to strong column weak beam yield mechanism. Based on different limit value of the axial compressive ratio, establish 3 and 4 grand frame structure models to carry out static nonlinear analysis and nonlinear time-history analysis.(3)Analyze the effects of the rigid connected infill walls to strong column weak beam yield mechanism. Based on different filling wall arrangement forms, establish 4 frame models to carry out static nonlinear analysis and nonlinear time-history analysis to determine the possible destruction during the earthquake.(4) Analyze the anti-earthquake performance of different moment augment factor of column frame structure models. Moment augment factor of column is the main method of current code to ensure the strong column weak beam yield mechanism. In this paper, 6 frame structure models with different moment augment factor of column are established and analyzed with the methods of static nonlinear analysis and nonlinear time-history analysis to determine the reasonable values of moment augment factor of column.