State-of-the-Art Review on the Influence of Diverse Dynamic Loads on the Applicability of Modal Analysis in Reinforced Concrete Structures

Reinforced concrete (RC) structures are essential to modern infrastructure, yet their dynamic behavior under various loading scenarios remains a major concern. Modal analysis, a core technique in structural dynamics, is widely used to determine natural frequencies, mode shapes, and damping ratios. However, its classical assumptions of linearity and time-invariance often fail under real-world conditions involving nonlinearities, degradation, and fluid-structure interaction. This paper reviews the influence of five major dynamic loads—earthquakes, wind, blasts, machinery-induced vibrations, and sea waves—on the effectiveness of modal analysis in RC structures. Based on an extensive survey of over ۸۰ scholarly studies, it explores how each load uniquely challenges the reliability of traditional modal parameters. Seismic and blast loads tend to cause abrupt stiffness degradation and significant shifts in modal properties. Wind and wave actions introduce amplitude-dependent damping and modal coupling effects. Machinery-induced vibrations require continuous tracking to prevent resonance and fatigue. The review evaluates the performance of classical linear models, modal pushover analysis, operational modal analysis (OMA), and emerging AI-enhanced hybrid approaches. It also identifies key limitations in current design practices, including inadequate damping representation, lack of full-scale validation, and disciplinary fragmentation. Future research should focus on developing adaptive, data-driven modal frameworks, integrating resilience-based design approaches, and implementing real-time structural health monitoring. By offering a unified perspective on load-specific modal behavior, this study aims to bridge the gap between theory and practice, enhancing the dynamic design and safety assessment of RC infrastructure systems.

کلیدواژه ها:

Reinforced concrete ، Modal analysis ، Dynamic loads ، Earthquake ، Blast ، Wind ، Vibration ، Wave loading