Vibro-Acoustic Analysis and Topology Optimization of Anti-Tetra Chiral Auxetic Lattices Driven by Different Colored Noises

Abstract

In this paper, we study vibro-acoustic behavior of auxetic sandwich panels subjected to different excitations and boundary conditions. The core of this panel has the auxetic feature (with negative Poisson’s ratio or NPR) with anti-tetrachiral honeycomb structure. Mechanical behavior of the core is formulated using theoretical relations presented for this kind of auxetic. Using the Finite Element Method, the modal analysis and spectral analysis of the structure are accomplished. Different random colored noises are applied as the system excitation. First, a parametric study is performed; and some interesting results are observed from investigating the effects of geometric parameters, boundary conditions, and noise color on the vibro-acoustic behavior of the structure. These parameters affect the natural frequencies, level of radiated sound, and mass of the structure. An optimization algorithm is applied to the geometrical parameters in order to simultaneously reduce the level of radiated sound and preserve the amount of total mass. By the use of the Genetic Algorithm (GA), we could achieve a remarkable noise attenuation gain. It is shown that the GA choses different optimized parameters for the structure according to the location of the load and frequency content of the load spectrum.

Flight Sound of an Insect Wing: Application of Metamaterial Concepts to Bioinspired Flapping Wings

“…This analysis should be performed separately by applying proper optimization techniques, e.g., as proposed in Refs. 33,34,35,36 , and is, thus, out of the scope of the present work.…”

Enhancement of the vibro-acoustic performance of anti-tetra-chiral auxetic sandwich panels using topologically optimized local resonators

“…The optimization results for the panel under full loading are presented in Figs. 19,20 and Table 8. The results of this case are similar to ones related to the local loading.…”

“…These have led to perform topology optimization studies to improve the behavior of metamaterials [18]. These studies include one-dimensional and twodimensional optimization of auxetic sandwich panels under harmonic excitations [19,20] . The aim in these works was to make use of geometrical parameters to improve the elastic modulus and to create gradient density in the structure to obtain a minimum radiated sound from the structure [21].…”

Investigation on the flexural properties of sandwich beams with auxetic core

“…On the other hand, auxetic metamaterials has been attracted special attention in recent years because of their unusual properties and many potential applications in various fields [12] including vibroacoustic applications [16][17][18], indentation resistance, fracture toughness, variable permeability, energy absorption [11,19,20] and other engineering fields such as packaging, biomedicine, sensors, automotive engineering, etc. [13,21].…”