Ramhormozian, ShahabBeskhyroun, SherifAlizadeh, Fatemeh2026-06-012026-06-012026http://hdl.handle.net/10292/21295This research investigates the seismic performance of the Asymmetric Friction Connection (AFC) and its enhanced form, the Optimised Asymmetric Friction Connection (OAFC), which serve as the primary energy-dissipating components of the Sliding Hinge Joint (SHJ) system for low-damage moment-resisting steel frames. The study focuses on developing, validating, and applying advanced finite element models and analysis (FEM/FEA) to interpret and expand upon the experimental findings previously conducted by Dr Shahab Ramhormozian, thereby providing a deeper understanding of the connection’s sliding behaviour and performance optimisation. The experimental programme by Dr Ramhormozian provided full-scale AFC and OAFC test data under quasi-static and dynamic cyclic loading, including bolt-tension evolution, clamping-force variation, and sliding hysteresis. In the present research, these results were analysed in detail to identify the mechanisms governing post-sliding bolt-tension loss and to establish the optimal installed bolt pretension level. It was observed that bolts tensioned to approximately 50–60 % of their proof load offered the most stable and repeatable sliding performance, whereas higher pretension levels induced excessive plastic deformations and accelerated tension degradation. Using ABAQUS/Standard, this study developed nonlinear FEMs for both AFC and OAFC assemblies, supported by mesh-convergence, element-type, and contact-interaction investigations to ensure accuracy and computational efficiency. The validated models adequately reproduced the experimentally observed hysteresis loops, clamping-force evolution, and bolt-tension variation. Incorporating partially deflected Belleville Springs (BeSs) in the OAFC models demonstrated markedly improved preload retention and smoother force–displacement responses. Furthermore, wear-induced degradation was simulated through temperature-controlled contraction, reproducing the experimentally observed reductions in clamping force and sliding resistance over cyclic loading. Comparative analyses showed that while the conventional AFC experienced up to 60 % clamping-force loss, the OAFC limited this reduction to 15–20 %, resulting in superior energy dissipation, improved self-centring capability, and enhanced durability. The developed FEM framework thus provides a validated, detailed computational tool for parametric studies and design optimisation of OAFCs and related low-damage seismic systems. Overall, this thesis refines and extends the interpretation of prior experimental results through advanced numerical analysis, contributing to the design and implementation of resilient, friction-based steel connections for low-damage seismic structures.enThesisOpenAccess