A novel membrane sound absorber based on the magnetorheological membrane (MRM) is developed for active sound absorption. Due to its good flexibility and stretch-ability, the MRM consisting of carbonyl iron particles (CIPs) and polydimethylsiloxane elastomer matrix can be easily deformed. The deformation of MRM is investigated by the digital image correlation method. The off-plane displacement is positively related to both of the CIPs mass fractions and magnetic field strength. The sound absorption performance of MRM sound absorber is investigated and it is found that the thickness of the membrane, CIPs mass fractions, and air cavity length behind the membrane significantly influence the sound absorption performance. The magnetic field can adjust the sound absorption frequency without affecting the high acoustical absorption coefficients. The double-layer membrane structure has two sound absorption peaks within the testing frequency range and further improves the frequency adjustability of the sound absorber. Therefore, it is expected to be a particularly promising alternative for active sound absorption. Finally, the numerical solutions calculated by the equivalent circuit method also support the experimental results.

开发了一种基于磁流变膜（MRM）的新型膜吸声器，用于主动吸声。由于其良好的柔韧性和可拉伸性，由羰基铁颗粒（CIP）和聚二甲基硅氧烷弹性体基质组成的MRM容易变形。通过数字图像相关方法研究了MRM的变形。平面外位移与CIP的质量分数和磁场强度均呈正相关。研究了MRM吸声器的吸声性能，发现膜的厚度，CIPs质量分数和膜后的气孔长度会显着影响吸声性能。磁场可以调节吸声频率，而不会影响高的吸声系数。双层膜结构在测试频率范围内具有两个吸声峰，并进一步提高了吸声器的频率可调性。因此，有望成为主动吸声的特别有希望的替代方案。最后，用等效电路法计算的数值解也支持实验结果。