Component Models for Steel Beam‐Columns With Hollow Structural Sections to Support the Practical Seismic Assessment of New and Existing Buildings

This paper presents the development and evaluation of engineering‐oriented models used in AISC 342–22 and the new Eurocode 8 Part 3 for the seismic assessment of steel buildings with steel hollow structural section (HSS) beam‐columns. These component models are critically important given the prevalence of HSS columns, particularly in existing space moment‐resisting frames that may require retrofits to meet the criteria imposed by modern design standards. The models are developed from an open‐access dataset of 275 physical experiments on HSS beam‐columns. The proposed recommendations, which are tailored for concentrated plasticity models, include empirical equations for predicting model parameters for both the first‐cycle envelope and the monotonic backbone of HSS members. Specific rules are also developed for concentrated plasticity deterioration models with adaptive backbone curves. The limit for force‐controlled HSS beam‐columns is recommended as . A reduction of 25% in the deformation parameters is proposed for beam‐columns with built‐up cross‐sections. Limitations of concentrated plasticity models are also discussed based on quantitative metrics.