Proposed reliable peak component factors for ductile light NSCs subjected to horizontal ground motions

Abstract

This paper aims to propose reliable factors that accurately capture the effect of target ductility of non-structural components (NSCs) on floor acceleration, velocity, and displacement demands at both the ground level and the upper building floors. A linear time history analysis (THA) was performed on four moment-resisting archetype buildings using historical and synthetic ground motions matched to the Montreal Site Class C uniform hazard spectrum (UHS) through frequency domain matching. The NSCs’ seismic demands and ductility-based modification factors were determined using uncoupled analysis, in which the equations of motion were solved using the Iterative Newmark Integration approach implemented in MATLAB. The seismic floor acceleration, displacement, and velocity demand amplitudes were reduced with increased NSC ductility, especially inside the resonance period range. The effect of ductility on the seismic acceleration demands was found to be significant near the resonance condition for the first three primary periods of the supporting structure. Conversely, the displacement and velocity demand were predominantly affected by the first primary mode. Specifically, for NSCs with moderate to high ductility levels, a 40%-60% decrease in demand was observed compared to NSCs exhibiting elastic behavior in the resonance condition. In contrast, the effect of ductility was minimal for out-of-resonance conditions and on ground-level seismic demands. Moreover, the sensitivity analysis on damping variations showed minimal impact on the proposed factors, further supporting their robustness. In conclusion, while ductility minimizes resonance effects on NSCs, a trade-off between the benefits of ductility and an acceptable damage level must be considered.