Study On The Constraint Action Between Plate On Joint Position Of Cold-formed Thin-walled Steel

Compared with the traditional structure,the cold-formed thin-walled steel structure has many advantages,such as economy,environmental protection and so on.Based on the basic section of crimped C-shaped steel,the steel structure team of Inner Mongolia University of Science and Technology has formed a new structural form of double-limb cold-formed C-shaped steel back-to-back cushion plate.This new cross-section member has been proved to have unique advantages in the application field of cold-formed thinwalled steel structure.In order to further expand the wider application of this new type of composite section members in the construction industry,this paper explains the direction combined with the theoretical formula,validates through the finite element simulation and test,and finally regresses and fits the relevant formula of the restraint coefficient of the plate group.a systematic study on the restraint effect of double-limb cold-formed Csection steel members was carried out.First of all,the paper analyzes the theoretical source of the semi-energy method of plate group constraints,and summarizes the main analysis process from ideal veneer buckling to plate buckling without considering plate group constraints and then to plate buckling considering plate group constraints.At the same time,the finite element analysis of the member is carried out by ANSYS,and different cold-formed thin-walled steel specifications,bolt spacing and nodal plate thickness are selected,that is,different cushion plate structures are modeled as the variable parameters of the research object,and the data needed to fit the constraint coefficients such as limit,buckling load,maximum and minimum stress of section and midplane compression displacement are obtained.Finally,with the help of MATLAB mathematical analysis software,according to the finite element simulation results,the calculation formula of plate group constraint coefficient of the member under the new section form is fitted.Experiments are carried out to verify the reliability of the results obtained by the finite element method and the accuracy of the regression formula of the constraint coefficient of the plate group.In the experiment,different specifications of section steel members are selected,and the axial compression buckling properties are tested,and the material properties of the specimens used for follow-up test analysis and ANSYS simulation modeling are obtained.The relevant data from elastic and plastic stage to judging failure stop test are recorded and analyzed,such as bending displacement curve,compression displacement curve,related stress change and so on.The results show that the member with this cross section has excellent buckling performance and the test data are reliable;at the same time,it is proved that the data error obtained by the finite element method is still within the limit,the overall trend is consistent,and the failure pattern is consistent.The simulation expansion data of the members are reliable.In this paper,through the finite element analysis and confirmatory test of a new type of cross-section member with cushion plate in the form of double-limb cold-formed Csection steel back-to-back,the buckling performance data related to the listed parameters are obtained,and the relevant calculation formula of the plate group constraint coefficient of the member is obtained by regression.on the basis of the existing effective width method of plate group constraint,the principle of mechanism action is expounded deeply.It provides more performance design basis for the practical application engineering of related components.