Optimization method of two-dimension solid-phase phonon crystal mixed mode band gap

A technology of phononic crystals and optimization methods, applied in special data processing applications, instruments, electrical digital data processing, etc., can solve problems such as limited lattice structure

Active Publication Date: 2013-09-18
BEIJING UNIV OF TECH
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  • Application Information

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Problems solved by technology

However, it is uncertain whether the obtained simple phononic crystal structure has room for further improvement in order to obtain better bandgap characteristics
It can be seen that the lattice structures that can be obtained by empirical summary and intuitive design methods are very limited; in addition, for some phononic crystal band gaps with specific functional requirements, such as solid phononic crystal XY and Z mixed mode band gap, the traditional design method is even more powerless

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  • Optimization method of two-dimension solid-phase phonon crystal mixed mode band gap
  • Optimization method of two-dimension solid-phase phonon crystal mixed mode band gap
  • Optimization method of two-dimension solid-phase phonon crystal mixed mode band gap

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Embodiment Construction

[0040] The present invention will be further described below in conjunction with drawings and embodiments.

[0041] In this embodiment, a two-dimensional square lattice solid-phase phononic crystal composed of two materials is studied. Material A is steel, its density ρ A =7780kg / m3, the material Lame constants are: λ A =122GPa,μ A =81GPa; material B is epoxy resin, its density ρ B =1180kg / m 3 , and the material Lame constants are: λ B =4.43GPa,μ B =1.59GPa.

[0042] The method flow chart of this embodiment is as follows figure 2 shown, including the following steps:

[0043] Step 1, perform initialization operation: the phononic crystal primitive cell is set to reflect symmetry about the x and y axes and 90° rotational symmetry around the z axis, at this time only 1 / 8 of the primitive cell is needed to describe the whole primitive cell. The phononic crystal primitive cell is discretized into a 20×20 square unit structure, and the length of the genetic individual binar...

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Abstract

The invention belongs to the technical field of phonon band gaps, and relates to an optimization method of a two-dimension solid-phase phonon crystal mixed mode band gap. The optimization method comprises the following steps: step 1, initializing; step 2, calculating an XY mode energy band and an Z mode energy band of a two-dimension solid-phase phonon crystal through applying a finite element method; step 3, constructing an objective function by the phonon crystal mixed mode band gap and calculating the fitness of genetic individuals; step 4, carrying out genetic operation to generate next generation of populations, enabling the populations to evolve forward, and continuously updating the populations; step 5, if the populations are stable, turning to the next step, otherwise, returning to the step 2; and step 6, taking the corresponding population of the obtained optimal result as an initial population, carrying out extension and discretization into 2M*2M square unit structures on each phonon crystal primitive cell, and optimizing calculating and iterating again. The optimization method overcomes the limitation of a traditional phonon crystal experience design, improves the capability of actively designing the phonon crystal structure needed by the band gap, enhances the designability of the phonon crystal, and improves the performance of the phonon crystal structure.

Description

technical field [0001] The invention belongs to the field of acoustic bandgap material design, and relates to a method for optimizing the bandgap of a two-dimensional solid-phase phononic crystal. Phase phononic crystal XY and Z mixed-mode bandgap characteristics. Background technique [0002] Within the bandgap of the phononic crystal, elastic waves are not allowed to pass through. Many applications of phononic crystals are based on its bandgap characteristics, therefore, it is necessary to artificially design a bandgap in a specific frequency range. Compared with three-dimensional phononic crystals, two-dimensional phononic crystals also have similar band gap characteristics, and are easier to artificially manufacture. When the elastic wave propagates in the (x, y) plane of the two-dimensional phononic crystal, it can be decoupled into an in-plane coupled wave mode (XY mode) and an out-of-plane shear wave mode (Z mode). If the designed two-dimensional phononic crystal c...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G06F17/50
Inventor 吴斌刘宗发何存富
Owner BEIJING UNIV OF TECH
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