This project utilizes recent developments in dynamical systems theory in the analysis of engineering dynamics problems. Specifically, local and global bifurcation techniques are used to predict dynamics behavior as a function of system parameters, as well as to describe them. The research focuses on four classes of systems, including the use of input waveform for the suppression of chaos in periodically forced oscillators, the stability of modes at rest in systems which have active modes undergoing chaotic dynamics, nonlinear dynamic interactions in rotating mechanical systems, and simple models for the dynamic response of mechanisms with flexible linkages. A widening gap between theoretical developments and applications in the field of nonlinear dynamics has occurred in recent years. This research is a direct attempt to bridge that gap by employing modern analytical and numerical tools in the investigation of specific mechanical systems.