Probabilistic assessment of seismic acceleration demands of ductile light NSCs in moderately ductile RC frame buildings

Abstract

This study investigates how the seismic demands of non-structural components (NSCs) are influenced by both their attachment ductility and the nonlinear behavior of supporting structures. The research focuses on acceleration demands at various building elevations and evaluates component damage states according to Hazus guidelines. Incremental dynamic analysis (IDA) was applied to evaluate both linear and nonlinear structural responses of four archetype reinforced concrete moment-resisting frame buildings. Ground motions, consisting of historical and synthetic records, were scaled to match Montreal’s uniform hazard spectrum for Site Class 'C' with a 2 % probability of exceedance per 50 years. NSC responses were assessed using an uncoupled analysis approach, implemented through iterative Newmark integration. Key findings demonstrate that increasing the ductility of NSC attachments reduces their acceleration demands by up to 140 % in elastic structures. When accounting for structural nonlinearity, acceleration demands decrease by 110 %, highlighting the conservative nature of elastic analysis assumptions commonly used in current design practices. These reductions are most pronounced for components with periods corresponding to the structure's fundamental mode, with the effect diminishing for higher modes. The research provides practical design implications by quantifying the relationship between attachment ductility, structural behavior, and component damage thresholds. The results indicate that a moderately ductile (μ≈1.5) NSC attachment provides optimal performance benefits while minimizing the risk of NSC damage, offering valuable insights for the performance-based design of NSCs.