Study On The Seismic Behavior Of The Ductility Staggered Truss Steel Framing

Staggered truss steel frame is a new structure,with great economy,while forming large space for two column spacing,which is in line with the development direction of China’s steel building structure,previous studies suggest that plastic hinge of staggered truss steel frame under cyclic load first appeared in the truss webs,then truss chord,last appeared in the column,which is a sign of structural damage,the structure exhibit brittle haracteristics.In order to improve the seismic performance of staggered truss steel frame,the task group proposed a concept of ductility staggered truss steel frame:under sereve earthquake,the plastic hinge of structure appears only on special segment in the middle of the truss,the rest of the structure maintain flexibility,the dissipation of seismic energy depend on plastic deformation of the central truss section(special segment),with the view to improve the capacity of energy dissipation and the ductility of the structure,and to facilitate post-earthquake repair.This paper use ABAQUS,a finite element analysis software,to analysis hysteretic behavior of staggered truss steel frame under cyclic loading,to build finite element model with bilinear strengthen the material constitutive relation,taking material nonlinearity and geometric nonlinearity C3D3 R solid elements into account,There are four sets of models in total,the three are staggered truss steel frames with dual channel chord,H-chord and double angle chord,and the last one is parameter models to study the impact on seismic performance of ductility staggered truss steel frame,By comparative analysis of hysteresis curves,skeleton curves,bearing capacity degradation,stiffness degradation,ductility factor and the energy dissipation coefficient of the models.It is concluded that,when the chord is of dual channel chord or H-chord,the hysteretic performance of ductility staggered truss is better than that of normalstaggered truss,when the chord is double angle,on the contrary;and the ratio of the length of special segment and height and ratio of the length of special segment and length of truss,the law of which impact on hysteresis properties of ductility staggered truss steel frame.studying the design method of ductility staggered truss steel frame proposed by the task group,one purpose of that is study seismic performance of ductility staggered truss steel frame proposed by the task group,the other one is to provides a data reference to the post test.