PUSHOVER ANALYSIS OF THE SPECIAL-SHAPED CFST EDGE-FRAME

摘要

The special-shaped CFST frame is a structural system which formed by L-shaped CFST prism and T-shaped middle column.Research and engineering practices show that this structural system has low bearing capacity and poor seismic performance.By doing Pushover analysis of 9 different sizes 2-span 3-layers edge-frame in the large finite element software SAP2000,effects of components' flakiness ratio and the yield bending moment ratio of beam and column on seismic performance of this kind of frame are shown.The frame's failure mechanism,Pushover curves,stiffness,ductility and drift angle between layers in the performance points are analysed.The results show the special-shaped CFST edge-frame has high bearing capacity and good elastic-plastic interlinear deformation capacity.Horizontal load bearing capacity and horizontal stiffness of the frame will be improved by raising flakiness ratio and bending moment ratio of beam and column.The frame's ductility decreases first then increases with the column's flakiness ratio increasing.When column's flakiness ratio equals 2.5,the frame has the best ductility.The frame's ductility decreases first then increases while bending moment ratio of beam and column increases.When bending moment ratio of beam and column equals 0.6,the frame has the best ductility.During column's flakiness ratio increases,the deformation of the frame from a shear type turns into a curved type gradually,and the frame layer displacement decreases.