Research On Hysteretic Behavior Of Steel Frame Filled With Cold-formed Steel Wall Structure System

Cold-formed steel wall-steel frame structure system is a new structural system,which developed from the application of the cold-formed steel thin-wall steel residentialbuildings, there is few research on it at present. The model of the low-rise cold-formedsteel wall-steel frame structure system(which is called DC structure system for short)and the steel frame filled with cold-formed steel wall structure system(which called NTstructure system for short) have been established by ANSYS program, the failure mode,shear force distribution between the wall and the frame, and the energy dissipationcapacity under both the monotonous and the cyclic horizontal load were researched.According to the research on the accurate model, two kinds of simplified models wereproposed, which were called WS model and XS model, and then the effectiveness of themodel was analyzed.The finite element analysis of the DC model under both the monotonous and thecyclic horizontal load indicates that the failure mode of this system is the strengthfailure of the wall; the share rate on the shear force of the wall is from70%down to57%, the share rate on the shear force of the steel frame is from30%up to43%; thehysteresis loops of this system are plump, the energy dissipation capacity is well, thewall is the main member to dissipating the energy in the earlier stages of loading, andthen is the steel frame.The finite element analysis of the NT model under both the monotonous and thecyclic horizontal load indicates that the failure mode of this system is the strengthfailure of the wall; the hysteresis loops of this system are plump, the energy dissipationcapacity is well, the wall is the main member to dissipating the energy in the earlierstages of loading, and then is the steel frame; the change of the mode of connection will change the shear force distribution between the wall and the frame and the fashion ofsuffering force of the columns of the steel frame significantly; the change of the ratio ofheight to width will change the loading capacity, with the increasing of the ratio ofheight to width, the loading capacity and the lateral stiffness will reduce; there is noobvious change when the positions of connection is changed，but the internal force ofthe beam changes obviously.The research of the simplified models indicates that the loading capacity and initialstiffness are in accordance with the original model within elastic range, the mode of theshear force distribution has big differences between the simplified models and theoriginal model. the energy dissipation of the simplified models of the wall is lower thanthe original wall in the earlier stages of loading, and bigger later; the simplified modelsof the BL system and DC system shows good consistency.