Deformation analysis of locally buckled steel compression members

Abstract A numerical study is presented on the local and overall interaction buckling behavior of steel compression members of welded box sections. Accurate moment-thrust-curvature curves ( M-P-Φ curves) of locally buckled stub-columns are first computed with residual stresses and initial out-of-flatness of component plates being taken into consideration. The computed M-P-Φ curves are then integrated along the member axis to obtain the overall load-deformation characteristics of compression members. The effect of initial out-of-straightness of the member is included in the procedures. The numerical results are compared well with available test results of eccentrically loaded box columns. The numerical results are further utilized to check the adequacy of design formulae proposed previously by the authors. It has been found that a slight modification to the original formulae leads to better design formulae.