Sound Transmission of Composite Meta‐Sandwich Panels With Tunable Thermosensitive Elastomers and Shape Memory Alloys

The acoustic behavior of a composite meta‐sandwich panel (CMP) under plane acoustic excitation was systematically investigated via theoretical modeling and experimental verification in this paper. A mechanical‐acoustic coupling model was formulated within the framework of first‐order shear deformation theory (FSDT) using Hamilton's principle. Subsequently, the sound transmission loss (STL) of the CMP was solved using the space harmonic series method combined with the velocity continuity condition. To validate the theoretical predictions, representative specimens were fabricated and tested using the standard reverberation‐anechoic chamber method. The comparison between experimental and theoretical results confirmed the reliability of the developed framework, with deviations between predicted and measured natural frequencies and STL remaining within 5% and 10%, respectively. Experimental results demonstrate that the STL of the CMP is maximally improved by 20% when the temperature increases from 25°C to 55°C under multi‐module activation. Moreover, progressive activation of thermosensitive functional modules leads to a continuous enhancement in acoustic attenuation performance, accompanied by an upward shift in natural frequencies. Finally, parametric analyses were conducted to reveal the influence of essential geometric and material factors on STL, and design guidelines were provided to improve the sound insulation capacity of the CMP. The results indicate that increasing the number of embedded shape memory alloys (SMAs) enhances structural stiffness and STL, while maintaining the elastomer‐to‐frame volumetric proportion and the core‐to‐total thickness ratio within 0.6–0.7 achieves a balance between rigidity and acoustic attenuation.