为提升水下结构的隐身性，改善常规的局域共振声学超材料（locally resonant acoustic metamaterials, LRAMs）在低频段（500 ~ 1 000 Hz）的吸声性能，基于局域共振耦合机理，提出了一种内嵌多个散射体且具有半径梯度变化的新型局域共振声学超材料。利用有限元法研究了LRAMs的带隙特性，分析耦合共振效应对声学超材料带隙特性的影响；并计算了LRAMs 5 000 Hz内的吸声系数，研究了散射体数量、形状、半径梯度和背衬厚度对吸声性能的影响以及1 000 Hz内的结构改变对吸收性能的调控机理。结果表明：新型LRAMs通过散射体之间的耦合共振效应可提升低频吸声性能，通过优化材料的结构参数能够进一步完善LRAMs的吸声性能。

To enhance the stealth of underwater structures and improve the low-frequency (500 ~ 1 000 Hz) sound absorption performance of traditional locally resonant acoustic metamaterials (LRAMs), a novel type of LRAMs incorporating multiple embedded scatterers with a radius gradient was proposed based on local resonance coupling. The band gap characteristics were investigated using the finite element method (FEM), and the influence of coupling resonance on band gap behavior was analyzed. The sound absorption coefficient within 5 000 Hz was calculated, and the effects of scatterer number, shape, radius gradient, and backing thickness on absorption performance were examined. Additionally, the modulation mechanism of structural modifications on low-frequency absorption below 1 000 Hz was explored. The results indicate that the novel LRAMs improve low-frequency sound absorption performance through the coupling resonance effect between scatterers, and further optimization of the material's structural parameters can enhance the absorption performance of the LRAMs.