Using strong nonlinearity and high-frequency vibrations to control effective mechanical stiffness
Jon Juel Thomsen
High-frequency excitation (HFE) can be used to change the effective stiffness of an elastic structure, and related quantities such as resonance frequencies, wave speed, buckling loads, and equilibrium states. There are basically two ways to do this: By using parametrical HFE (with or without nonlinearity), or by using external HFE along with strong nonlinearity. The first way has been examined for many different systems, and analytical predictions exist that has been repeatedly confirmed against numerical simulation and laboratory experiments. The current work contributes knowledge on the other way: Combining the method of direct separation of motions with results of a modified multiple scales approach, valid also for strong nonlinearity, the stiffening effect is predicted for a generic 1-dof system, and results are tested against numerical simulation and ((it is planned)) laboratory experiments.