Here,multi-channel structures were stacked layer by layer to form an acoustic metamaterial,and its muffling characteristics and mechanism were studied with theoretical analysis,numerical simulation and experimental verification.To broaden muffling frequency band,the optimal combination scheme of cavity length was proposed with genetic algorithm,and the optimization logic was discussed.The results showed that this structure can be regarded as an acoustic waveguide tube connecting multiple side-branched Helmholtz resonators,and its transmission loss curve has multiple continuous resonance peaks to be able to realize broadband muffling;properly adjusting length and width of its cavity,increasing structural thickness and constructing non-uniform arrays can improve broadband muffling performance of the structure;when optimizing structures with different sizes,genetic algorithm always establishes as many single Helmholtz resonators with stronger muffling abilities as possible to obtain the maximum muffling bandwidth;experimental results verify the effectiveness of structural broadband muffling;the above results can provide a reference for pipeline muffling in narrow spaces.
万方数据
维普
