Optimal design method of curved bar periodic structure based on band gap

Abstract

The invention relates to the technical field of structural dynamics, in particular to an optimal design method of a curved bar periodic structure based on a band gap. The curved bar periodic structurecomprises a plurality of unit cell models which are connected with one another, each unit cell model comprises two curved bars which are intersected with each other and are in rotational symmetry, and the optimal design method comprises the following steps: taking the curvature of each curved bar as a design variable, and limiting the value range of the design variable; calculating a mass matrixof the unit cell models and a rigidity matrix of the unit cell models based on the design variables; establishing a frequency wave vector equation of the unit cell models based on the mass matrix of the unit cell models and the rigidity matrix of the unit cell models; solving the frequency wave vector equation to obtain a response relationship between the design variables and the band gap frequency of the curved bar periodic structure; and substituting the design variables into the response relationship and calculating the minimum value of the band gap frequency. According to the optimizationdesign method, the curved bar periodic structure can be optimized on the basis of elastic wave propagation characteristics, so that vibration and noise reduction of the curved bar periodic structure in a low-frequency range is realized.

Description

technical field [0001] The present disclosure relates to the technical field of structural dynamics, in particular to an optimal design method for a periodical structure of a curved bar based on a band gap. Background technique [0002] In the fields of vehicle transportation, aerospace and ships, etc., periodic structure refers to a repetitive overall structure composed of the same components sequentially, that is to say, periodic structure refers to the structure composed of several beams, rods, cables or plates, etc. A structure that is connected along a predetermined direction in a certain way, for example, a vehicle skeleton and an aircraft skeleton are periodic structures. [0003] Vibration and noise in periodic structures propagate in the form of elastic waves, and elastic waves in periodic structures have band gap characteristics. Specifically: when elastic waves propagate in periodic structures, elastic waves in certain frequency ranges cannot pass, called the ban...

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Problems solved by technology

[0004] At present, the research on the propagation characteristics of elastic waves in periodic structures mainly focuses on straight rod periodic structures, but for curved rod periodic structures, not only has no elastic wave propagation analysis model been established, nor has there been an in-depth study of elastic wave propagation characteristics. The control method makes it impossible to optimize the geometric structure of the curved rod periodic structure, resulting in the inability to obtain a curved rod periodic structure with an ultra-wide (ultra-wide frequency range), ultra-low (ultra-low overall position of the frequency range) bandgap, and cannot realize The vibration and noise reduction function of the curved bar periodic structure in the low frequency range naturally cannot provide a certain reference for engineering practice

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