M$21$ Explain the importance of structural dynamics in civil engineering, particularly in the analysis and design of buildings, bridges, and other infrastructure. Discuss how structural dynamics involves the study of how structures respond to dynamic loads such as wind, earthquakes, and vibrations. Describe the methods used in structural dynamics analysis, including modal analysis, response spectrum analysis, and time history analysis. Highlight the significance of understanding structural dynamics in ensuring the safety, serviceability, and resilience of civil engineering structures, especially in regions prone to seismic activity or other dynamic forces.