Design and Uncertainty Optimization of Pneumatic Helmholtz Resonance‐Type Soft Acoustic Metamaterials

Traditional acoustic metamaterials (AMMs) typically have fixed structures, making it difficult to conveniently control their bandgaps. In this article, a pneumatic Helmholtz resonance‐type soft acoustic metamaterial ( P ‐HRSAMM) made of soft silicone rubber material is designed. The bandgap characteristics of the P ‐HRSAMM under the influence of local resonance mechanisms and Bragg scattering mechanisms through finite element calculations are analyzed. By combining these two bandgap mechanisms, new bandgaps can be obtained, and by applying different air pressures, the structure of the bandgaps can be controlled. Additionally, a surrogate model is used to analyze the effects of uncertainties in material, geometric, and pressure parameters on the band structure of the P ‐HRSAMM. Based on the trained surrogate model and genetic algorithm, the uncertainty optimal design of P ‐HRSAMM for maximizing bandgap width is performed. The results show that the P ‐HRSAMM made with soft silicone rubber can achieve bandgap tuning through pressure adjustment. After uncertainty optimization design, the total bandwidth of P ‐HRSAMM can reach 934.24 Hz.