Harnessing post-buckling deformation to tune sound absorption in soft Helmholtz absorbers. (15th October 2021)

• Record Type: Journal Article
• Authors: Gao, Nan; Qu, Sichao; Li, Jian; Wang, Jiao; Chen, Weiqiu
• Is Part Of: International journal of mechanical sciences. Volume 208(2021)
• Publication Date: 2021-10-15
• Subjects: Soft material -- Helmholtz resonator -- Post-buckling deformation -- Perfect sound absorption -- Mechanically tune; Mechanical engineering -- Periodicals; Génie mécanique -- Périodiques; Mechanical engineering; Maschinenbau; Mechanik; Zeitschrift; Periodicals; 621.05
• DOI: 10.1016/j.ijmecsci.2021.106695
• Languages: English
• ISSNs: 0020-7403

Abstract

Highlights: Integrate the soft hyperelastic material into the main structure of Helmholtz resonator (HR) to design a star-shaped soft Helmholtz absorber, whose acoustic characteristics can be tuned by harnessing its post-buckling deformation. Combine two star-shaped HRs with different wall-thickness to design a ventilated and mechanically tunable absorber to achieve asymmetric sound absorption and perfect sound absorption by applying specific and respective compression loads. The sound absorption of the proposed pair of HRs can be real-time tuned effectively and repeatedly by mechanical loading and unloading. Abstract: Helmholtz resonator (HR) has always been an important part of artificial sound-absorbing materials, most of which however cannot be tuned in real time and hence have a limited scope of applications. In this work, we integrate for the first time the soft hyperelastic material into the main structure of HR to design a star-shaped soft Helmholtz absorber. The soft HR exhibits different post-buckling deformation behavior when its wall-thickness varies, which further yields different acoustic characteristics. By combining two star-shaped HRs with different wall-thickness, we are able to achieve asymmetric sound absorption when specific and respective compression loads are applied to the two HRs. In addition, high sound absorption at various frequencies can be obtained via different combinations of the applied loads. Due to the perfect capability of reversible large deformation of soft hyperelastic materials, the sound absorption of the proposed pair of HRs can be real-time tuned effectively by mechanical loading and unloading. In other words, the acoustic switch controlled by mechanical load can be realized. The proposed soft absorber has an obvious practical application value, and also provides an important illustration for the design of soft and tunable acoustic devices. Graphical Abstract: Image, graphical abstract