特殊中心支撑钢框架非耗能构件抗震承载力需求研究

The concentrically braced steel frame structure has been widely used in multi-storey and high-rise steel structures because of good seismic resistance performance and economical efficiency, light weight and high strength of steel material. As energy dissipation element, the bracing resists seismic lateral force under axial force transmitting to beam and columns. When the bracing buckles or yields under severe earthquake, the demands of beams and columns will increase greatly due to the redistribution of forces. Therefore, beams and columns must have sufficient strength and stiffness to ensure the demand under severe earthquakes, otherwise it is very easy to cause overall structural collapse with rapid decline of stiffness and appearance of weak story. Based on the finite element simulation of nonlinear time history analysis, the dynamic earthquake response process of centrically braced steel frame is showed, and the effects of different conditions on the demands of columns and beams are studied. Since some studies have exposed the inadequacy of the design regulations about non-dissipative components of centrically braced steel frame structure in the current code, supplementary design methods are proposed.