Dissipation energy in sound-absorbing poroelastic material

Rate-independent energy dissipation mechanisms in fiber-matrix material systems

Rate-independent energy dissipation associated with high-strain high-stress behavior of the material is considered. This rate-independent energy dissipation is associated with damage and relative motion inside the fiber-matrix material system. Simple mechanical models for energy dissipation were presented to facilitate the understanding of the phenomena. Three mechanisms for internal energy dis...

Sound absorption by clamped poroelastic plates.

Measurements and predictions have been made of the absorption coefficient and the surface acoustic impedance of poroelastic plates clamped in a large impedance tube and separated from the rigid termination by an air gap. The measured and predicted absorption coefficient and surface impedance spectra exhibit low frequency peaks. The peak frequencies observed in the absorption coefficient are clo...

An optimal design and application of sound-absorbing material made of exploded bamboo fibers

An acoustic material made of exploded bamboo fibers has been newly developed from an ecological viewpoint. The basic acoustical properties of the material as the sound absorption coefficient, the characteristic impedance, and the propagation constant were measured for the frequency range between 50 and 6400 Hz by the transfer function method using two-microphone impedance tubes. In order to des...

Vortex Dissipation in Superfluid Third Sound Flows

A sound absorbing metasurface with coupled resonators

An impedance matched surface is able, in principle, to totally absorb the incident sound and yield no reflection, and this is desired in many acoustic applications. Here we demonstrate a design of impedance matched sound absorbing surface with a simple construction. By coupling different resonators and generating a hybrid resonance mode, we designed and fabricated a metasurface that is impedanc...