A piezo-shunted kirigami auxetic lattice for adaptive elastic wave filtering

Abstract

Abstract. Tailoring the dynamical behavior of wave-guide structures can provide an efficient and physically elegant approach for optimizing mechanical components with regards to vibroacoustic propagation. Architectured materials as pyramidal core kirigami cells combined with smart systems may represent a promising way to improve the vibroacoustic quality of structural components. This paper describes the design and modelling of a pyramidal core with auxetic (negative Poisson's ratio) characteristics and distributed shunted piezoelectric patches that allow for wave propagation control. The core is produced using a kirigami technique, inspired by the cutting/folding processes of the ancient Japanese art. The kirigami structure has a pyramidal unit cell shape that creates an in-plane negative Poisson's ratio macroscopic behavior. This structure exhibits in-plane elastic properties (Young's and shear modulus) which are higher than the out-of-plane ones, and hence this lattice has very specific properties in terms of wave propagation that are investigated in this work. The short-circuited configuration is first analysed, before using negative capacitance and resistance as a shunt which provides impressive band gaps in the low frequency range. All configurations are investigated by using a full analysis of the Brillouin zone, rendering possible the deep understanding of the dynamical properties of the smart lattice. The results are presented in terms of dispersion and directivity diagrams, and the smart lattice shows quite interesting properties for the adaptive filtering of elastic waves at low frequencies bandwidths.

Mechanical Metamaterials and Their Engineering Applications

“…The thermal heating to sinter the LAGP powder removes the polymer scaffold and the empty micro‐channels within the ceramic template was filled with polymer (polypropylene melt or liquid epoxy) through resin impregnation to finally form the solid‐state electrolyte. Other applications of mechanical metamaterials in electronics also include the manufacture of sensors, actuators, and filters, which typically involve the use of highly compliant topologies such as origami, kirigami‐inspired structures and other auxetics. For instance, Ning et al synthesized 3D mesostructures by compressive buckling of 2D kirigami patterns piezoelectric thin‐film micro‐actuators for vibratory excitation and precise control in various electronic and biomedical devices …”

Damping control for improvement of acoustic black hole effect

“…This adaptive concept is different from active devices [15,16] in the sense that the time scale required in the temperature regulation is much smaller than the one of the phenomena to be controlled. It may however be qualified as semi-active [17,18] since some energy is required to heat the damping layer according to the objectives. The aim of the heat control is to tune the mechanical properties of the viscoelastic material: it is well known for years that their stiffness and damping properties are strongly dependent on frequency and temperature [19,20,21].…”

Numerical investigations and experimental measurements on the structural dynamic behaviour of quasi-periodic meta-materials

“…In terms of material properties, there are various cases that show in-plane and out-of-plane elastic properties. For example the dynamical behaviour of a 2D periodic waveguide, which exhibits in-plane elastic properties (Young's and shear modulus) compared to out-ofplane ones, are described in terms of elastic wave propagation in [3,4]. The possibility of designing such smart materials or structures, that can partially reduce mechanical waves on certain frequency ranges, is addressed in [5,6,7].…”