Phononic crystal material structure design method based on extended isogeometric analysis method

Abstract

The invention discloses a photonic crystal material structure design method based on an extended isogeometric analysis method. By changing the shape of the scatterer, the phononic crystal material with wide sound insulation frequency band and low sound insulation frequency is designed. The computational grid of the extended isogeometric analysis method is independent of the geometry inside the structure, so that the computational grid does not need to be reconstructed when the shape of the scatterer changes; when the energy band structural characteristics of the phononic crystal material are analyzed by adopting an extended geometric analysis method based on LR-NURBS, small-scale grids are adopted near a scatterer interface, and large-scale grids are adopted in other areas, so that the precision can be improved, and the time can be saved. The shape of the scatterer is described by adopting an NURBS spline function, so that the scatterer in any complex shape can be constructed. The scatterer obtained by the method is smooth in shape and can be directly used for design; the method can accurately describe phononic crystal periodic cell elements with complex shapes, and realizes the design of the structure of the phononic crystal material by seamless combination of CAD and CAE.

Description

technical field [0001] The invention belongs to the field of structural design of acoustic metamaterials, in particular to a method for designing a structure of a phononic crystal material based on an extended isogeometric analysis method. Background technique [0002] Phononic crystal is a new type of artificial acoustic functional material with periodic structure and acoustic / elastic band gap. Elastic waves are periodically modulated by elastic constants during propagation, which may produce phonon band gaps, that is, the propagation of elastic waves in a certain frequency range is suppressed. It is precisely because of the acoustic characteristics of phononic crystals: peculiar band gap, localization, and negative refraction characteristics that it has broad application prospects in vibration isolation, noise control, acoustic waveguide devices, and acoustic lenses. [0003] The structural design of phononic crystal materials includes the shape of scatterers and their di...

AI Technical Summary

Problems solved by technology

However, since the band gaps obtained are often not in the frequency range to which the human ear is sensitive, the band gap frequencies of most phononic crystals reported so far are in the ultrasonic range or the high-sound range, which cannot achieve the ideal sound-isolation frequency bandwidth and The state of low sound insulation frequency

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