Study On Seismic Behavior Of Beam Flange Opening Weaken Type Of New Weak-axis Joints For H Shaped Column

At present,most of the research on the steel frame of I-shaped column is concentrated in the strong-axis direction of I-shaped column,but the study of the weak-axis direction of I-shaped column is relatively few;and the study of the space steel frame with the joint with the weak-axis of the working column is scarce;the traditional weak-axis wedge-shaped stiffened plate connections have poor plastic rotational capacity and easy failure of the column web.On the basis of previous research,a new type of weak-axis connection node is proposed,and the finite element software ABAQUS is used to carry out numerical simulation and analysis on the form of the node.In this paper,a new type of weak axis joint model is established by using the finite element software,which is compared with the traditional wedge-shaped stiffened plate type weak-axis joint and the end-plate connected weak-axis joint.The new weak-axis of beam flange connections of circular holes weaken treatment and contrastive analysis of the no-weaken new weak-axis joint.The results show that the beam opening weaken type of new weak-axis joints has realized the purpose of plastic hinge displacement.Although the bearing capacity is declined,but the hysteretic performance,ductility and energy dissipation capacity are better,and the seismic performance is better.Through the finite element software analysis of the opening length of the weakened zone of the beam(a),the adjacent holes center distance(b),the hole center distance to the beam edge(c),the opening diameter(D)and the opening number(N),the effect of the plastic hinge formation,the hysteresis curve,the skeleton curve,the bearing capacity,the ductility and the energy dissipation capacity of the joint specimens.The reasonable value range of all kinds of weakened parameters of the beam opening weaken type of new weak-axis joint is obtained through analysis and research,providing reference for practical engineering application.For the application of the weak-axis connection node form in practical engineering,two space steel frame of three-trussed two-layer two-straddle is designed in this paper,which have the beam opening weaken type of new weak-axis joints and the no-weaken new weak-axis joint,and the finite element analysis is carried out.Analysis results show that the plastic hinge of the beam opening weaken type of new weak-axis joint is formed on the weakened zone onthe beam,effectively preventing the brittle fracture of the frame,and its hysteretic curve is more full,the ductility and energy dissipation capacity are better,the stiffness degradation is slow and the seismic ability is good.