Optimal bandgaps of a spiral structure based on locally resonant phononic crystals

Abstract

A spiral locally resonant phononic crystal (LRPC) with the optimal bandgaps (BGs) between 20 and 250 Hz is proposed. The single factor analysis of three key geometric parameters (the thickness of spiral elastic beams, the side length of square scatterers and the spirals’ turns) are performed to obtain corresponding influences on BGs, two-factor (the thickness of spiral elastic beams and the side length of the square scatterer) and seven-level experiment under the four fixed spirals’ turns are designed to obtain optimal BGs with better low-frequency broadband properties. According to numerical experiments, BG data of present spiral LRPCs can be calculated by finite element method (FEM). Relationships (i.e., the relationship between the starting frequency of the first BG and the two factors, the relationship between the bandwidth of the first BG and the two factors, and the relationship between the bandwidth of the second BG and the two factors) are further obtained using the response surface methodology (RSM). The optimal BGs with better properties are finally calculated using the interior point method.

Flexural wave bandgap properties of phononic crystal beams with interval parameters

“…Further, in order to increase the width of the bandgap and reduce the beginning frequency of the bandgap, Chen et al [21] optimized the hexachiral phononic crystal by integrating the genetic algorithm into the secondary development platform of ISIGHT. By using the response surface method, Zhai et al [22][23][24] and Liu et al [25] established the approximate relationship between the beginning frequency or ending frequency of the bandgap and some geometric parameters of two-dimensional locally resonant phononic crystals, and used this relationship to optimize the structures. Li et al [26] established the inherent relationship between bandgaps and topological features through a deep learning based data-driven method.…”

Band Gaps and Transmission Characteristics Analysis on a Two-Dimensional Multiple-Scatter Phononic Crystal Structure

“…He also presented an array of periodic coating on a thin plate, which were investigated by FEM simulations and experiments [25]. Furthermore, some researchers proposed a generalized structural optimization scheme to optimize 2D PC structures [26][27][28].…”