Alper Erturk - Leveraging nonlinear dynamics in mechanical and electromechanical structures

This talk will review some of our recent and ongoing efforts on the leveraging of nonlinear dynamics in passive and active structures, spanning from nonlinear energy harvesting using piezoelectric smart structures to nonlinear vibration attenuation via distributed bistable attachments in metastructures. Following our early work on using an electromechanical bistable Duffing oscillator for frequency bandwidth enhancement in piezoelectric energy harvesting, we will discuss monostable counterparts exploiting designed hardening nonlinearities for primary and secondary resonances, as well as modeling and analysis using the method of harmonic balance along with experimental validations. Beyond these intentionally introduced nonlinearities, inherent material and dissipative nonlinearities and their interaction with designed nonlinearities, and circuit nonlinearities with non-ideal diode dynamics in rectification will be discussed briefly. Examples will also be given on combining nonlinear structures with nonlinear circuits for bifurcation suppression, including a piezoelectric nonlinear energy sink interface for wideband vibration attenuation, along with an outlook on digitally programmable nonlinear piezoelectric structures toward task switching and tunability. The use of bistable attachments in locally resonant metastructures will also be discussed for amplitude-dependent wideband vibration attenuation (to overcome the limitations of the locally resonant linear bandgap) by leveraging chaotic dynamics.