Experimental Study And Finite Element Analysis On Seismic Behavior Of Steel Frame With Haunch Reinforced Section Connections

Haunch Reinforced Section connections can improve the mechanical property of nodes such as ultimate bearing capacity and displacement,ductility coefficient,ductility coefficient,plastic deflection etc.In recent years,many scholars have conducted extensive research on seismic capacity of new ductile node,and have achieved rich results.But dynamic characteristics of structure under strong earthquake are complicated,in experimental study on hysteretic behavior of beam-column joints cumulative additive effects of many factors such as structure of space effect,secondary beam of confining effect,plastic hinge formation and development mechanism in the steel frame can't be fully considered.In order to investigate the seismic behavior of steel frame with haunch reinforced section connections,a 1:3 scale 2-story space steel frame with haunch reinforced section connection is designed,specimen is composed of north and south steel frame through column-and-brace,space steel frame is studied by pseudo-static test and finite element analysis,to study loading-displacement hysteretic curve,skeleton curve,lateral stiffness,inter-story displacement angle,bearing capacity degeneration,plastic energy dissipation capacity of the framework.Comparative test and finite element specimen failure results,specimen shows plastic failure.All plastic hinges of eight haunch reinforced section connections move to 1/2 beam height from the bottom of the axillary plate.Beam-end flange and web have great plastic deformation.In the test eight haunch reinforced section connections have not weld cracks.Two steel frame stress uniformly,and plastic development achieves better consistency.Hinge support of column base releases moment effectively,ensure that the column don't damage before the steel frame.The results of test and finite element analysis indicate that the loading-displacement hysteretic curves are full,especially in the plastic stage the area of hysteretic loop is larger than test.The skeleton curves of test and finite element analysis shows S pattern,and the trend is consistent.The inter-story displacement angle of test ranges from 4.29% to 5.99%;and the finite element analysis ranges from 5.41% to 6.35%,the ratio of the displacement angle is more than 3.0.The steel frame with haunch reinforced section connections exhibits better energy dissipation capacity under cyclic loading.Equivalent viscous damping coefficient ranges from 0.3590 to 0.3797,energy dissipation is fully.Under equal amplitude loading,the capacity degradation coefficient of two steel frames increase slowly,and space synergistic effect improve the bearing capacity of steel frame.After yielding of the structure,test and finite element analysis of lateral stiffness change same.