This comprehensive volume discusses Lagrange's Equations and Hamilton's Principle, followed by a wide range of topics of current interests in practice and research including random dynamics and nonlinear dynamics in the context of fluid (acoustics) and structural systems and their interactions. Very high dimensional systems are given special attention including notable mentions of asymptotic modal analysis and reduced order models for macroscopic and nanoscale systems. Recent developments in fluid structure interaction in high speed flows are also included. The useful reference text benefits professionals, researchers, academics, graduate and undergraduate students in the field of aerospace, civil and mechanical engineering.