Adaptive membrane-type acoustic metamaterial with autonomous tuning to incident sound fields

自适应膜型声学超材料，可自主调谐入射声场

• 批准号: 455631459
• 负责人: Dr.-Ing. Felix Langfeldt
• 金额: --
• 依托单位: Institute of Sound and Vibration Research
• 依托单位国家: 德国
• 项目类别: WBP Fellowship
• 财政年份: 2020
• 资助国家: 德国
• 起止时间: 2019-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/455631459?language=en
• 关键词: Adaptive; membrane; type; acoustic; metamaterial

Membrane-type acoustic metamaterials (MAM) consist of a thin pre-stressed membrane with masses attached to the membrane. Even though these metamaterials are very lightweight and thin, they exhibit narrow frequency bands (so-called anti-resonances) in the low frequency range with very high sound insulation values - much higher than a homogeneous wall with the same mass. This makes MAM a very promising solution for noise control applications with strict constraints on the mass and size of noise control treatments. The narrow bandwidth of the anti-resonances, however, is a considerable inhibiting factor for the application of MAM to noise sources with changing frequencies of tones (e.g. generated by rotating machines). The objective of this project is to demonstrate for the first time an adaptive MAM which is capable of autonomously tuning itself to an incident sound field with a spectrum containing both broadband and tonal components. In the project, an adaptive control algorithm will be developed in conjunction with actuation methods and sensors integrated on the MAM to achieve improved broadband and tonal noise reduction, compared to the passive MAM. In particular, the adaptive MAM will be capable of identifying deviations between a tone in the noise source spectrum and the anti-resonance frequency of the MAM and it will adapt itself within milliseconds to adapt the anti-resonance frequency to this tone. The sensitivity of the adaptive MAM with respect to non-linearities as well as changes of the dynamic properties of the MAM (e.g. due to temperature changes) will be investigated. The adaptive control algorithm will be developed to be robust with respect to these disturbances, thus enhancing the applicability of the adjustable MAM to more practical noise control applications. As a final result of this project, an experimental demonstrator of an adjustable MAM will be built and tested for different noise source configurations.

膜型声学超材料（MAM）由一层附着质量的预应力薄膜组成。尽管这些超材料非常轻且薄，但它们在低频范围内表现出窄频带（所谓的抗共振），具有非常高的隔音值-比具有相同质量的均匀壁高得多。这使得MAM成为噪声控制应用的一个非常有前途的解决方案，对噪声控制处理的质量和尺寸有严格的限制。然而，反共振的窄带宽对于将MAM应用于音调频率变化的噪声源（例如由旋转机器产生的噪声源）是一个相当大的抑制因素。该项目的目标是首次展示一种自适应MAM，该MAM能够自动调整自身以适应包含宽带和音调成分的频谱的入射声场。在该项目中，将开发一种自适应控制算法，结合MAM上集成的驱动方法和传感器，与无源MAM相比，实现更好的宽带和音调降噪。特别是，自适应MAM将能够识别噪声源频谱中的音调与MAM的反共振频率之间的偏差，并且它将在几毫秒内自适应以使反共振频率适应该音调。将研究自适应MAM对非线性的敏感性以及MAM动态特性的变化（例如由于温度变化）。自适应控制算法将被开发为对这些干扰具有鲁棒性，从而增强可调MAM在更实际的噪声控制应用中的适用性。作为该项目的最终结果，将建立一个可调MAM的实验演示器，并针对不同的噪声源配置进行测试。