The Study Of Cold-formed Steel Wall's Shear Bearing Capacity In Green Farm House

With the continuous deepening of the new rural construction,a new type of green housing system has emerged constantly,and cold-formed thin-walled steel structures are one of them.This kind of structural system basically has a few types of components,is simple to assemble,and has a high overall utilization rate of land.Promoting the use of this type of structural system for the construction of green farmhouses can effectively solve outstanding problems such as a small area of cultivated land in rural areas and unreasonable layout of buildings.As an important part of the house structure,the steel keel combination wall has in-depth study of its shear performance has very important engineering application value.In this paper,based on the characteristics of cold-formed thin-walled steel composite wall,a finite element model considering thin-walled steel,covered wallboard and self-tapping screw joint work is established.The main conclusions are as follows:First,the three monotonously loaded composite wall specimens in[25] were chosen as validation models for numerical simulation.The SHELL181 four-node shell element in ANSYS software was used to simulate the wall steel keel and the cladding wallboard,and considering the actual deformation state,the non-linearity of the wall material was highly geometrically nonlinear with the connection of the components;the steel skeleton post and the guide beam were connected.It is articulated;the effect of self-tapping screws connecting the steel skeleton with the wall panel is approximately replaced by coupling.The finite element numerical simulation results are in good agreement with the experimental values,which verifies that the numerical simulation method is feasible.On the premise of verifying the validity of the simulation method,the influence rules of steel frame column spacing,self-tapping screw spacing,wall-height ratio,and steel keel strength on the shear performance of the composite wall were analyzed.The results show that the change of steel keel material strength has no significant effect on the shear strength of the composite wall;the shear strength of the wall is different with the reduction of the distance between the steel frame pillars,the reduction of the wall-height ratio,and the self-tapping screws.The degree of increase and bearing capacity change significantly.In this paper,the recommended values of the shear strength of the common double-sided(OSB board + gypsum board)composite wall are given by numerical calculation,which can be used as a reference for the design of this type of composite wall.Secondly,with the powerful nonlinear analysis function of ANSYS software,the nonlinear numerical analysis of the shear wall performance of the cold-formed thin-walled steel composite wall with a size of 3.6m(width)× 3m(height)was performed to investigate the opening of the hole.The shear strength of the wall under different influence factors such as area ratio,hole type and location.The simulation data and graphs show that the greater the proportion of the opening area of the opening-combination wall is,the lower the maximum bearing capacity of the wall is;no matter if the window-opening hole or the position of the door opening and the hole is changed,the shear strength of the wall will not change significantly.The deformation of the ends of the steel keel columns on both sides of the caverns is severely damaged and there is a pronounced "wavy" type of torsional deformation.In the design of the wall,it is necessary to strengthen the key treatment;the section of the pressured side columns is severely buckled and the wall is not open.Body ductility is less than the opening of the wall combination.Finally,different empirical formulas are used to calculate the specific values of the shear strength of the composite wall under the ratio of the area of the different openings.The data analysis results show that the shear strength of the wall is slightly different according to different empirical formulas,and the results are compared with the numerical simulation results.In contrast,the empirical calculation formula tends to be conservative in calculating the shear strength of open-hole walls.For practical engineering design,the empirical formula can provide a certain amount of safety reserves.