Inverse determination of porosity from object's resonances

摘要

An alternative technique combining vibroacoustography and the finite element method for measuring the porosity parameter P and damping of a chalk sphere immersed in water is presented. This technique is based on the detection of the sphere resonance frequencies which will be compared to the finite element calculations. An optimization procedure based on the least squares method is performed in order to evaluate the "effective" Young's modulus and damping parameters. Hence, porosity can be estimated by an inverse expression from the effective Young's modulus.