Patent attributes
An acoustic system is provided for the perfect absorption of bending waves. The acoustic system includes a longitudinally extending substrate (plate or beam) defining upper and lower opposing major surfaces. At least two mechanical resonators are coupled to the upper major surface and separated by a distance dimension that may be based on a fraction of a magnitude of the wavelength of a selected bending wave. Each mechanical resonator includes a rigid mass component and a connecting element. The mechanical resonators are configured to block or absorb bending waves that propagate through the substrate. The connecting elements maintain the rigid mass component an elevated distance from the upper major surface of the beam when in a rest position. The connecting element can be a spring and damper; a flexible rubber/plastic component with an axial stiffness; or a base connecting component with a flexible arm, optionally with vibration damping.
