The study on mechanical property for Welded haunch-reinforced Seismic connections of Steel Frame

To study on the mechanical property for haunch-reinforced seismic connection, the simplified calculation model of haunch connection is introduced. The force analysis of beam with haunch connection is carried through to research (beta)value influence on mechanical property of haunch connection; Combining American design specification with Chinese design specification, the design procedure for welded haunch connection is shown, and the differences in design between two countries are summarized. At last, it is studied through beam-column joints case analysis that the influence of the different node parameter on the mechanical property of haunch connection. The results can be got that with the increase of the (beta)value, the beam moment at column face becomes smaller, which will be better to protect the beam form brittle fracture. But if beta is larger than one, beam web shear in the haunch region will increase. In the design the reasonable beta value should be close to one but less than two. When haunch height is invariant, with the increase of haunch length,in became smaller; the beta value and the top and bottom beam flange groove weld stress reduce gradually; The required minimum section area of haunch flange became larger; The axial force of haunch flange and haunch web shear increase gradually. The reasonable haunch length should be as close to the middle of the (0.5 to0.6) times of height beam as possible. The reasonable haunch flange section area should make beta close to (beta)(min), such materials are made full use.