Porosity-dependent velocities of longitudinal and transverse waves in dry porous materials

Abstract

New relations are presented to better evaluate the longitudinal and transverse velocities in porous materials under the dry state, respectively. The models are based on semi analytically derived bulk and shear moduli-porosity correlations for dry porous materials. The accuracy and robustness are validated by fitting the published elastic waves-porosity data of different porous materials and a further sensitivity analysis, respectively. The accuracy of the proposed models is averagely higher than that of the empirical Phani’s equation and theoretical Ramakrishnan’s equation. There is an advantage over the Ramakrishnan’s equation to predict the zero-porosity velocity from the data lack of dense porous specimens. The proposed models have a good predictive performance for porous materials with critical porosity and can provide the value of critical porosity, but attention also should be paid to increased sensitivity in this case.