Estimation of ultimate capacities of Moment-Resisting Frame's subassemblies with Mid-Storey Pin connection based on elastoplastic local buckling

This research proposes a novel method of Mid-Storey Pin Moment-Resisting Frames’ (MSP MRFs) ultimate capacity estimation. Shell and solid numerical models with initial imperfections are defined and calibrated against the experimental results. Parametric studies are conducted, presenting the influence of structural parameters on the performance and failure mode of the frame dictated by the elastoplastic local buckling of members. It is shown that commonly used control over column-to-beam plastic moment ratio is insufficient; the need for column-to-beam stiffness ratio consideration is highlighted. Finally, innovative yet simple equations are proposed to estimate the frame's storey drift capacity and ultimate strength ratio.