Ultrasonic waves propagation in fluid-saturated materials

This work deals with the application of an ultrasonic nondestructive technique to characterize poroelastic materials; the results of ultrasonic experiments in the laboratory are used to investigate the wave propagation models in a poroelastic medium filled with fluid. The laboratory precision is required to extract, from measurements, powerful parametric models describing the wave propagation by mean of a frequency-domain inversion technique. The ultrasonic equipment consists of a water immersion system using non-destructive testing-type transducers. In order to simulate the mechanical behavior of sediments, the device under investigation is a composite multilayer saturated with water. Immersion experiments are made at frequencies ranging from 0.3 to 3 MHz. The physical parameters of the used material are estimated and attention is paid to the evolution of the phase-velocity dispersion and the absorption over the frequency band