Research On Cooperative Working Performance Of Cold-formed Steel Composite Wall-Steel Frame Structure

Cold-formed steel composite wall-steel Frame structure (CFSW-SF) is a new type of structure derived from the application process of cold-formed steel framing structure. The research on the cooperative working performance and design theory of this new structure are virtually nonexistent.This thesis firstly studied the cooperative working performance between cold-formed steel composite wall(CFSW) and steel frame(SF), and the stiffness degradation rules were put forward through the previous tests,then the seismic behavious of CFSW-SF was studied by time history analysis,at last the design approach of this new structure was put forward.Method and conclusions of the investigation were listed as following:1. Based on the lateral stiffness theory of CFSW and SF,the differential equations of the cooperative working performance between them were established by continuous method, three sets of the calculation formula for the lateral displacement and the distribution of shear force were obtained by solving the equations.2. Numberical simulations of cold-formed steel composite wall and steel frame with nine different stiffness ratio were carried out using the ANSYS program to study the cooperative working performance and shear force distribution between them. The results show that: principle of linear superposition between cold-formed steel composite wall and steel frame was verified,and the distribution principle of shear force was in accord to stiffness.3. Based on the test data, the stiffness degradation rules of CFSW with different panels were studied,which were proved to be identical,when angular displacement value of CFSW is 1/100,the equivalent stiffness is 40% to 50% of the elastic stiffness.4. Three-dimensional numerical model of CFSW-SF was established,then the horizontal static load analysis, modal analysis and elasto-plastic time history analysis were carried out,which indicated that simplified calculation formula of natural period was available for CFSW-SF and the "Space Effect" could be negelected when calculating the internal forces and displacements.5. Design advices of CFSW-SF were proposed. In elastic stage, the distribution principle of shear force between CFSW and SF was based on elastic stiffness; In elastic-plastic stage, the distribution principle was based on equivalent stiffness.