Akademik Veri Yönetim Sistemi
Composites Part B: Engineering, cilt.313, 2026 (SCI-Expanded, Scopus)
Porous acoustic foams are widely used for noise control but inherently lose sound absorption effectiveness when mechanically compressed, which significantly limits their performance in confined or load-bearing applications. To counteract this limitation, this study used open-cell foams impregnated with shear stiffening gels (SSGs) and shear thickening fluids (STFs), with and without carbon nanotube (CNT) reinforcement, to create innovative composite foams with tunable stiffness under deformation. A multi-faceted approach, including fabrication process, rheological analysis, microstructural and mechanical characterization, and comprehensive acoustic testing using an impedance tube, was employed. The results indicate that the macroscopic acoustic performance of the composites is controlled by the viscoelastic properties of the fillers. SSG-based composites, with a high storage modulus (G′), act as stiffness-controlled barriers. Their rigidity under low-to-moderate compression creates a significant acoustic impedance mismatch, resulting in high sound absorption and sound transmission loss (STL) and effective low-frequency (LF) reflection. In contrast, STF-based composites are managed by the loss modulus (G″) and dynamic viscosity, allowing them to maintain acoustically open viscous dissipation pathways even under severe compressive strains (60–80 %). This prevents the performance collapse seen in densified foams. Static compression serves as an external tuner, pre-stressing the additives to enhance stiffness in SSG or viscosity in STF. Across all conditions, CNT reinforcement further enhanced performance by increasing structural rigidity and promoting multi-scale sound scattering. Compared with untreated foams, the optimized composites delivered markedly greater LF attenuation, a range in which conventional porous materials typically perform poorly while retaining functionality under severe compression. These characteristics suggest potential for lightweight, multifunctional acoustic solutions in automotive, aerospace, and high-speed train applications, where installation space is constrained and sustained compressive loading is expected.