Adaptive genetic algorithm enabled tailoring of piezoelectric metamaterials for optimal vibration attenuation

Abstract

Piezoelectric metamaterials with shunt resonant circuits have been extensively investigated for their tunability in bandgaps. However, the vibration attenuation ability induced by the electromechanical coupling is generally weaker than that of mechanical metamaterials, limiting their applications in engineering practice. This research presents a non-uniform piezoelectric metamaterial beam with shunt circuit parameters optimized by an adaptive genetic algorithm for tailoring the vibration attenuation zone. First, the non-uniform piezoelectric metamaterial beam is modeled for transmittance analysis and verified by the finite element method. By simultaneously tuning the resonance frequencies and the resistance of the shunt circuits, it is conceptually demonstrated that the attenuation zone can be broadened, and the undesired localized vibration modes can be mitigated. Subsequently, two optimization strategies are proposed respectively for two typical vibration scenarios. The inductances and the load resistance in the shunt circuits constitute the set of design variables and are optimized by the adaptive genetic algorithm. Dedicated case studies are carried out, and the results show that the objective-oriented circuitry parameters can greatly enrich the design freedom, and tailor the transmittance profile according to a given vibration spectra. As compared to the conventional uniform and the graded piezoelectric metamaterial beams, the proposed design provides superior vibration attenuation performance and demonstrates a promising approach for tailoring piezoelectric metamaterials systems.

Adaptive piezoelectric metamaterials leveraging non-uniform local resonators

“…The small frequency spacing in Figure 2(a) yields a wider overall bandgap region as compared to the unsuccessful aggregation with the completely separated adjacent bandgaps in Figure 2(c) under larger frequency spacing. In addition, as previous studies have indicated, using load resistor R can suppress those sharp local resonant peaks to achieve a continuous attenuation region [17,18]. However, the smoothed bandgap by adequately tuning the load resistance R results in a pseudo bandgap where the transmission ratio becomes large, i.e., at around -10dB (around 0.3) for wave attenuation [13,14,18].…”

“…T is the transformation matrix of propagating wave of the th i non-uniform unit cell. The overall transmission ratio is defined as the ratio of the displacement of the transmitted wave to the displacement of the incident wave [14,15,17], given as, 1) and (2).…”

“…These investigations, however, primarily focus on metamaterial designs with periodically arranged arrays of identical local resonators. More recently, the concept of graded metamaterials where material or geometric properties of the unit cells are allowed to vary slightly has been explored, aiming at enhanced wave attenuation performance [13][14][15][16][17][18]. For example, with spatially varying LC resonant frequencies, multiple LC resonant bandgaps can be created within the bandgap region, forming an overall enlarged bandgap.…”

“…On the other hand, the continuous attenuation region after smoothing with resistance may become a pseudo bandgap with poor attenuation characteristics. Relatively few papers offer solutions to this issue, with exceptions including some optimization analyses [13,17].…”

Kresling origami-inspired electromagnetic energy harvester with reversible nonlinearity

“…geothermal [1], solar [2] and tidal energies [3]) to reduce the usage of fossil energy. Ubiquitous vibrational energy [4][5][6] has great potential as the sustainable energy source for lowpower electronics [7]. Three major energy harvesting methods have been proposed to convert vibrations into electricity, namely, electromagnetic [8][9][10], piezoelectric [11][12][13][14] and triboelectric transductions [15][16][17].…”