Three-dimensional resonating metamaterials for low-frequency vibration attenuation.

Area of Science:

• Materials Science
• Acoustics
• Mechanical Engineering

Background:

• Additive manufacturing allows complex phononic crystal and metamaterial designs.
• These materials exhibit spectral gaps (stopbands) that block elastic wave propagation via Bragg scattering or local resonance.
• Metamaterial properties are tunable by altering the unit cell design.

Purpose of the Study:

• To introduce a novel design approach for metamaterials with internal resonators.
• To demonstrate a three-dimensional stopband across the irreducible Brillouin zone.
• To achieve lower frequency stopbands than Bragg scattering alone or reduced dimensions.

Main Methods:

• Developing a new metamaterial design incorporating internal resonators.
• Utilizing numerical simulations to predict and analyze stopband behavior.
• Conducting experimental validation of the designed metamaterials.

Main Results:

• Confirmed the existence of a three-dimensional stopband over the irreducible Brillouin zone.
• Achieved significantly lower stopband frequencies compared to Bragg-type phononic crystals.
• Demonstrated tunability of the stopband frequency range by modifying the metamaterial design.

Conclusions:

• The proposed metamaterial design effectively creates tunable, low-frequency, three-dimensional stopbands.
• These metamaterials offer advantages in achieving desired elastic wave control in smaller volumes or at lower frequencies.
• Potential applications include aerospace, transport, and precision engineering components requiring vibration suppression.