Numerical assessment of the cyclic behaviour of structural steel members subjected to biaxial bending

In recent decades, there has been extensive research on the behaviour of steel structures under seismic actions. While the monotonic behaviour of steel elements subjected to uniaxial bending is well understood, there is still a need to investigate the cyclic behaviour and energy dissipation capacity, especially in relation to metal elements subjected to biaxial bending. This is of paramount interest for seismic analysis and performance assessment of steel buildings. Modelling and damage assessment criteria derived for members subjected to uniaxial bending may not be entirely appropriate for the seismic analysis of buildings composed of structural steel members subjected to biaxial bending. Therefore, this research aims to investigate the behaviour of steel members subjected to biaxial cyclic bending and compare it to behaviour under uniaxial loading conditions. To this end, detailed 3D finite element analyses are conducted to examine the effects of bidirectional lateral cyclic loading on the hysteretic response of steel members under different uniaxial and biaxial lateral displacement‐controlled load paths. The numerical results presented in this paper provide an insight into the influence of biaxial loading on the behaviour of steel members in terms of backbone curves and deformation capacity, and indicate that biaxial cyclic loading paths can significantly affect the rotation capacity of steel elements.