Structural dynamics plays a critical role in assessing the response of civil engineering structures to dynamic loads such as seismic events, wind forces, and vehicular traffic. Discuss the fundamental principles of structural dynamics, including vibration analysis, modal analysis, and dynamic response spectra. Examine the challenges associated with predicting and mitigating structural vibrations, considering factors such as resonance, damping, and nonlinear behavior. Furthermore, explore the role of structural control technologies, such as active and passive damping systems, in enhancing the resilience and performance of civil engineering structures subjected to dynamic loading conditions.