The Hollow Axial Seismic Performance Of Double Channel Built-Up Battened Column Under Cyclic Loading

Built-up members are widely used in steel structure factory building,steel platform,light steel structure system because of its economy,the rational distribution of section material,building-layout flexibility,high degree of industrialization,the good torsional performance and many other advantages.Due to the particularity of its cross-sectional composition,the critical stress decreases for its bending stiffness is lower than the bending stiffness of the solid web member,the additional deformation caused by shear can not be ignored.The domestic research on the plate column is mainly based on the theoretical derivation and the stability test of the axial compression,The research contents include the problems of elastic and elastic-plastic stability,bearing capacity and buckling under the axial compression and the biasing load.The effection of initial imperfection,slenderness ratio,layout and slenderness ratio on the mechanical behavior of the steel lattice columns were investigated by static test method,stability theory and numerical methods but there were no details about the double channel built-up battened column in domestic standards and specifications.Therefore the study on hysteretic behavior of the double channel built-up battened column and know the properties of the seismic action had significant important in engineering practice.The cyclic loading experiments on the double channel built-up battened column were conducted with consideration of influence of such parameters as the spacings of batten plates,the line stiffness of batten plates,stiffeners spacing and setting on hysteretic behavior of the double channel built-up battened column.Also hysteretic and skeleton curves,the load-story drift values for various loading stages and seismic behavior index were obtained.The results show that the reduction of the plate spacing in the plastic hinge region can effectively improve the bearing capacity and ductility of the specimen,and ensure the double channel built-up member work together well.The stiffener can effectively relieve the local buckling of the plate and increase the energy dissipation capacity of the specimen.With the increase of the axial compression ratio,the stiffness and bearing capacity of the specimens are accelerated,and the energy dissipation is weakened,it is bad for the structure in earthquake.The plate line stiffness of the specimen which meets the regulatory requirements,if the line stiffness continues to increase,the effection of the hysteretic is smaller.Then the restoring force model could be achieved through test data by fitting the skeleton curve and stiffness of each level loading,which could contribute to establish the mathematical model used for seismic nonlinear analysis of steel frame structure and also could provide testing data for actual use of special staggered truss steel frame specimens in engineering structure.