Nonlinear dynamics of high-frequency excited mechanical systems

(Ph.d.-study). High-frequency excitation of a mechanical structure may affect its linear as well as its nonlinear properties. Applying high-frequency excitation to instability-prone structures (e.g., pipes conveying fluid, columns with follower loads, beams subjected to axial forces) may increase or decrease their domain of stability. Also, the nonlinear post-critical behavior can be altered, e.g., by changing types of local bifurcations, enhancing/decreasing global stability, and eliminating/creating chaotic dynamics. These effects opens up the possibility of using high-frequency excitation for designing structures with specific linear and nonlinear properties, e.g., for use in light-weight structures operating at high speed.