A Theoretical Calculation Model of H-Section Steel Members for Biaxial Bending Moments

To investigate the development mechanism of sectional plastic stress and biaxial bending moments of H-section steel members prior to local buckling subjected to monotonic and cyclic loading, extensive parametric analysis models were established in ABAQUS. These models explicitly accounted for different axial force ratios, plate width-thickness ratios under different loading angles, verifying the applicability against existing experimental data. Based on the results of finite element analysis, the effects of various factors on the development of normal stresses in the cross-section were thoroughly investigated. A semi-empirical semi-theoretical calculation model was established to address biaxial loading in H-section steel members, considering bidirectional displacement, the form of normal stress distribution, and the relationship between the biaxial bending moments. By comparing the model with finite element results, it was observed that the model effectively predicted the progression of biaxial bending moments development subjected to biaxial loading in H-section steel members. This model provides a more convenient design approach for considering the partial plastic development of the cross-section in bidirectional flexural design.