<p>Accurate estimation of deformation and strength capacities in structural members is critical for effective seismic design and performance evaluation. Traditional methods rely on standardized experimental loading protocols, which often overlook influential parameters such as structural system type, fundamental period, and earthquake ground motion characteristics. This generalization can lead to inaccurate assessments of structural behavior under seismic loading. The present study aims to address this gap by developing tailored loading protocols for six representative structural systems, each spanning a range of fundamental periods. The selected ground motions are categorized into short-duration (SD) and long-duration (LD) events to reflect diverse seismic scenarios. Realistic seismic behavior, including stiffness and strength degradation and pinching effects, is incorporated into the structural models. To quantify cumulative damage demands, approximately 36,000 nonlinear time-history analyses were performed. The resulting structural responses were analyzed using the rainflow cycle counting method and subjected to statistical interpretation to identify dominant deformation patterns. A simplified predictive function is also proposed to estimate displacement amplitudes efficiently. The findings reveal that ductile frames (Types 3 and 6) require fewer load cycles to represent their seismic behavior accurately, whereas stiffer and less ductile frames (Types 2, 4, and 5) necessitate more cycles due to their limited deformation capacity and higher brittleness. Overall, the proposed loading protocols offer a system-specific and performance-based approach to characterizing seismic demands, thereby improving the accuracy and reliability of seismic design and resilience assessment strategies.</p> Graphical abstract <p></p>