Research On Seismic Performance Of Steel Frame With Reduced Beam Section Connections

The steel structure has good ductility, which is considered to have good seismic performance. However, in previous earthquakes, steel structure buildings mostly occurred the local brittle failure at the joints of beam and column. To solve this problem, scholars put forward the new design method of ductility node, that is by improving the connection form of beam-column joints, forcing the plastic hinge appeared on the beam which is far away from the beam-column joints, by the shifting of the plastic hinge to protect the joint weld and avoid brittle fracture occurs at the beam-column joints. In this paper, experimental and finite element method are used to study the seismic behavior of the steel frame with a weakened flange.First of all, the monotonic loading contrast experimental study on the static elastic stage was carried on by using the flange weakening steel frame structure and the traditional steel frame structure. The two steel frame structures are compared and analyzed from the aspects of structural stiffness and internal force distribution.Subsequently, the shaking table test of the two steel frame structures is carried out. The dynamic performance, internal force distribution, hysteretic behavior and failure mode of the two steel frame structures are studied in the elastic stage and elastic-plastic stage by the step loading test.Thereafter, the steel frame structure test results and finite element results of the two steel frame structures were compared. Meanwhile, the two steel frame structures'finite element calculation results are compared and analyzed, and the conclusions obtained from the finite element calculation and experimental results were compared. Analysis results show that the finite element calculation method can be used in the research of structural seismic performance.Finally, to make the results more representative, three five-story two-span steel frame structure were designed, respectively using traditional node, flange weakening node and partly using the flange weakening node. The seismic behavior of the three steel frame structures is studied, by using the finite element method.