Iranian Society of Acoustics and Vibration and Avecina Journal of Theoretical and Applied Vibration and Acoustics 2423-4761 11 2 2025 07 01 Renovation of modified Biot's theory for modeling of the nanocomposite porous materials: A theoretical and experimental acoustical study 161 183 728762 10.22064/tava.2025.2053152.1261 EN Mohamad Mirmasoumi Acoustics Research Lab., Department of Mechanical Engineering, Amirkabir University of Technology, Tehran, Iran. Abolfazl Hasani Baferani Department of Mechanical Engineering, Tafresh University, Tafresh, Iran. Abdolreza Ohadi Acoustics Research Lab., Department of Mechanical Engineering, Amirkabir University of Technology, Tehran, Iran. 0000-0001-6514-4089 Journal Article 2025 02 11 <span style="font-size: 12.0pt; font-family: 'Times New Roman',serif; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">In this paper, the modified Biot’s theory is revised to predict the acoustic performance of nanocomposite porous materials more accurately, based on the nonlocal elasticity theory. The governing equations are derived for a transversely isotropic porous medium. The transfer matrix method is developed for the first time to obtain the absorption coefficient by introducing two non-local parameters, solid and fluid, to consider non-local effects. Subsequently, several nanocomposite foams are produced by various multiwall carbon nanotubes to validate the theoretical results. Different mechanical, acoustical, and non-acoustical properties of produced samples have been experimentally measured or calculated. Sound absorption for various solid and fluid nonlocal parameters is presented and compared with the corresponding absorption coefficient experimentally obtained from the impedance tube test. The obtained results show that by ignoring the fluid nonlocal effect, the experimental results agree well with the theoretical predictions based on modified Biot’s theory in wave propagation for large values of the solid nonlocal parameters.</span> https://tava.isav.ir/article_728762_dde914801ac24ad301838417ae092e45.pdf