Structural identification of a prototype pre-stressable leaf-spring based adaptive tuned mass damper: Nonlinear characterization and classification

The current paper focuses on a prototype adaptive TMD. Its design concept is based on pre-stressable leaf-springs that are controlled by piezoceramic (PZT) stack actuators. Experiments performed on the prototype showed that it is continuously tunable in a broad frequency range. Moreover, they revealed that the device exhibits structural nonlinearities. The current paper focuses on the structural identification of the prototype and attempts for the first time to characterize and classify the observed nonlinearities. Several experiments at different PZT voltage levels are performed. The results indicate PZT voltage dependent nonlinear softening and hardening stiffness. Based upon these observations, static experiments and proper data-pooling techniques, an effective “global” model for the nonlinear stiffness is derived. The estimated nonlinear model is finally validated upon static experiments as well as more realistic operational cases, that are vibrations of the prototype under typical ground excitation.