The Research On Mechanical Performance Of The High Strength Cold-formed Thin-walled Steel About Local Buckling

As a form of structure,the steel structure has been gradually developed all over the world in recent years.Due to the plentiful advantages,structural styles have been become various and cross section form has been become increasingly complex at the same time.In the past,thin-walled cold-formed steels were mainly used as frame members in the construction of portal frame structure with small and medium span,and now are mostly used for bearing members,the cold-formed thin-walled steel framing system presents a booming development in the world.With diligence development of steel structure production process,application of high strength cold-formed thin-walled steel have been rised in our country.However,the design theory and code are still developing slowly compared with developed countries.It is necessary to reform the related design theory to guide the pratical engineering.High strength cold-formed thin-walled steel has been more and more applied in industrial and civil buildings in our country under this background.In this paper,the stress of high strength cold-formed thin-walled steel component performance were studied.In this paper,a finite element(FE)model was developed to investigate the local buckling stress properties and bearing capacity performance of the high strength cold-formed thin-walled steel members after the compressive and flexural buckling.The FE model was considered the initial geometric imperfection.Research on the mechanical performance of compressive and flexural members under various parameters.The following conclusions may be drawn with the limitation of the research in this paper:(1)On the basis of using the finite element software ABAQUS and referring to the existing test data of members,choosing the reasonable material constitutive model,compressive and flexural cold-formed thin-walled type models were established.After numerical simulations about relevant test data,the simulation and the test analysis results were compared.It indirectly proved the correctness of the finite element model of compressive and flexural members.(2)The wall thickness of 0.6 mm,G550 level built-up high strength cold-formed thin-walled C steel rolled edge columns are made a series of axial compression buckling stress performance analysis.Considering the initial defects and material nonlinear,lots of simulations were finished to study the influence of broad ratio and slenderness ratio on the axial pressure bearing capacity by use of the S4 units.And then many preliminary studies about the high strength cold-formed thin-walled steel columns under axial compression using partial strip were done.In order to obtain conclusions,the strengthening effects of different reinforcement position and different width plate in the same position are compared.And it can be used for reference to compatible projects.(3)Considering the initial defects and material nonlinear,many researchesare made about G450 level high strength cold-formed thin-walled C steel rolled edge steel members with the wall thickness of 1.0mm or less.By use of the S4 units,the influence of width-to-thickness ratio,width,thickness and span on the ultimate bearing capacity of flexural members are studied.And then the results of the existing tests about low strength steel components under flexural force were compared with the results of this paper.And the influence of strength increasing for bearing capacity of flexural members were researched.