Research On The Overall Stability Of Austenitic Stainless Steel 304 Welded T Section Members Under Axial Compression

Stainless steel structures can satisfy the demand of architecture aesthetics,and their corrosion resistance is remarkable.China has promulgated Technical specification for stainless steel structures(CECS410:2015)to develop stainless steel structures in 2015.The previous research of structural stainless steel mainly focus on the behaviour of coldformed sections,welded box-sections and welded H-sections.However,study on welded stainless steel T sections is less in and abrord.This research foucs on the overall buckling behaviour of welded stainless steel T section members under axial compression by experimental and numerical results.The main research work and achievements are as follows:(1)The material test of austenitic stainless steel S30408 was conducted,and the static mechanics index was obtained.The applicability of existing constitutive models for stainless steel was verified;(2)The residual stress of austenitic stainless steel plates and welded T section was investigated by using sectioning method,and simplified residual stress distribution models were proposed.(3)The finite element model(FEM)of stainless steel welded T section axial compression member has been established by using ABAQUS.This model has been proven to be effective by comparing with existing compressive test data.(4)Through parametric analysis,the influence of constitutive model,the initial bending,initial twisting,and residual stress on the overall stability was in-depth studied.The results show that the initial twisting can significantly improve the elastic buckling capacity of members with small slenderness ratio,residual stress,while the residual stress has a direct negative effect on the stability factor.Besides,the constitutive model and initial bending have a relatively small impact.(5)The results of FEM were compared with two design codes for structural stainless steel.It is found that for T section axial compression members with large slenderness ratio,for flexural-torsional buckling mode,Chinese design code is slightly unsafe,and Eurocode is very unsafe.However,for flexural buckling mode,Chinese design code is conservative,and Eurocode is slightly unsafe.