Biaxial bending moments calculation model based on stress distribution for H-section steel members under different loading paths

To explore the biaxial bending development mechanism of H-section steel members under different cyclic loading paths, we conducted a parametric analysis involving various axial force ratios, plate width-to-thickness ratios, and loading angles. Three loading paths were considered, including linear, rectangular, and triangular loading paths. Finite element models were established in ABAQUS and validated for accuracy using existing experimental data. Based on the finite element analysis results, a methodology for determining the form of normal stress distribution was derived by analyzing the mechanism of biaxial interactions in H-section steel members. By establishing a relationship between the normal stress distribution and the biaxial bending moments, a semi-empirical semi-theoretical calculational model was developed to simulate the entire process of biaxial bending and compression loading at reverse point in H-section steel members under different loading paths. The validity of this model was confirmed, as it demonstrated effective prediction of the complete development trends of biaxial bending moments for H-section steel members. This model establishes the basis for seismic design of Hsection steel members subjected to biaxial loading conditions.