Fracture prediction for square hollow section braces under extremely low cycle fatigue

This paper examines the extremely low cycle fatigue (ELCF) fracture of concentrically loaded square hollow section (SHS) braces subjected to cyclic loading. Numerical analyses are presented for both individual bracing members and integrated into braced frames (CBFs). The behaviour was predicted using solid finite element (FE) simulations that employed a ductile model nonlinear damage evolution rule. FE model, which validated data from experiments, could adequately predict hysteretic response ELCF cracking process. coupled effects instabilities (i.e. local global buckling) on performance were assessed, rotation capacity prior quantified. quantified then incorporated fibre-based models CBFs as member-level criterion. structure-level able accurately capture complex interactions between frame components, i.e. columns, beams, brace–gusset–plate? connections beam-to-column connections, hence replicate overall CBFs, specifically, two-storey chevron frames. influence cross-section member slenderness evaluated importance considering in development limits highlighted. combined member- simulation approach is proposed an accurate efficient means assessing seismic CBFs.