Finite element models and 3D numerical simulations of novel steel joints for progressive collapse mitigation

This paper presents a comprehensive finite element investigation of a novel steel joint detail designed to enhance progressive collapse resistance. The proposed configuration utilizes stainless steel pins (SSPs) and tying plates to improve tie force capacity and rotational performance in steel connections. Building on earlier experimental validations, a refined three-dimensional finite element model was developed, calibrated against static test results, and employed for extensive parametric analyses. The study examines the effects of SSP diameter and tying plate thickness on loading capacity, deformation, and failure modes under column loss scenarios. Results demonstrate that the innovative joint detail satisfies directional strength and ductility requirements, achieving significantly improved rotational capacity and load redistribution compared to conventional connections. These findings provide clear design guidance for optimizing steel joints in structures that require enhanced robustness against progressive collapse. A 3D FE model of novel SSP-retrofitted steel joints was developed and validated against static tests. Non-symmetric modelling with geometric imperfections significantly improves prediction accuracy. The 3D joint reached 0.23 rad rotation and exceeded UFC tie-force requirements in both directions. Parametric analysis showed SSP diameter and tying plate thickness govern capacity and failure mode. Design guidance is provided, including recommended SSP and tying plate dimensions for collapse design.