Multifunctional acoustic and mechanical metamaterials prepared from continuous CFRP composites.

Area of Science:

• Materials Science
• Acoustics Engineering
• Mechanical Engineering

Background:

• Achieving carbon neutrality requires lightweight porous structures with dual acoustic and mechanical properties.
• Increased functionality in such structures often leads to undesirable weight gain, limiting applications.

Purpose of the Study:

• To introduce a novel lightweight structural design combining carbon fiber reinforced polymer (CFRP) composites with mechanical and acoustic metamaterials.
• To evaluate the mechanical and acoustic performance of this innovative composite structure.

Main Methods:

• Fabrication of a novel CFRP composite structure incorporating mechanical and acoustic metamaterials.
• Experimental analysis of the structure's mechanical properties (strength, energy absorption, resilience).
• Acoustic testing to assess sound insulation and absorption capabilities, focusing on broadband noise reduction and low-frequency performance.

Main Results:

• The developed CFRP composite structure demonstrates a balance of lightweight construction, high strength, and exceptional energy absorption.
• The structure achieves broadband noise reduction through metamaterial-based local resonance and impedance matching.
• Exceptional sound insulation with a bandwidth of nearly 1000 Hz, surpassing the traditional mass law, and superior low-frequency sound absorption below 300 Hz compared to melamine sponge.

Conclusions:

• The proposed multifunctional lightweight superstructure offers a novel approach for designing advanced materials.
• The structure's unique acoustic and mechanical properties are suitable for weight-sensitive applications aiming for energy efficiency.
• This design advances the development of materials that decouple performance from weight.