Title：Multifunctional Piezoelectric Metamaterial Systems    
Date：24th Jan 2018 10:00-11:00am
Location：A402

Abstract:

Elastic metamaterials (EMMs) with artificially engineered microstructures possess some unique properties including negative refraction, negative modulus, negative effective density, to name a few. Researchers have been attracted to explore the applications of EMMs for various kinds of purposes, one of which is low frequency vibration suppression. The ability of EMMs for vibration suppression arises from their band gap phenomenon due to the out-of-phase motion of the introduced microstructures (local resonance). On the other hand, the applications of EMMs have also been extended into the field of energy harvesting by integrating certain energy transduction components, such as, piezoelectric transducers.

In this seminar, I will talk about the recent work in our group on the modelling and design of piezoelectric metamaterial / metastructure systems to achieve multi-functionalities: vibration suppression and energy harvesting. First, I will cover the simplified lumped parameter model of piezoelectric metamaterial systems and the corresponding distributed parameter model of piezoelectric metamaterial beams. The later represents a more practical implementation. Then, I will introduce the design of a modified metamaterial system with internally coupling springs to achieve multiple band gaps for wideband vibration control. The corresponding distributed parameter model of piezoelectric metamaterial beam with internal coupling is also developed and the benefits for both vibration suppression and energy harvesting will be discussed. Finally, I will introduce our very recent effort in the modelling of a piezoelectric phononicmetamaterialbeam, which possesses both Bragg Scattering band gap and local resonance induced band gap. A one-dimensional piezoelectric composite finite element is derived and the predicted transmittance from our FE model confirms the existence of two types of band baps and demonstrates the influence of piezoelectric effect on the band gaps and energy harvesting performance.