Dynamic behavior of steel frames: influence of material yielding and hysteretic damping mechanisms

Recent research has increasingly focused on the inelastic behavior of steel frames under severe dynamic forces, which can lead to plastic deformation, damage accumulation, and potential collapse. In such conditions, structures must dissipate significant energy - a property facilitated by steel’s ductility, enabling large deformations and force redistribution beyond yield limits. This study evaluates the nonlinear dynamic response of planar steel frames, particularly highlighting the role of steel-yielding in inducing hysteretic damping. The analysis employs an elastoplastic material model with plasticity monitored using the refined plastic-hinge method (RPHM). The model incorporates residual stresses, cross-sectional plastic resistance, and second-order effects from large displacements and rotations. The numerical approach integrates the finite element method (FEM) with the Newmark scheme and Newton-Raphson iterations, providing insights into material nonlinearity, energy dissipation, and structural stability under dynamic excitation. Numerical simulations of two steel frames clearly illustrate the influence of hysteretic damping caused by material yielding, demonstrating its critical impact on dynamic structural response.