Theoretical Study of the Mechanical Properties by Using the Acoustic Signature

Abstract

Acoustic wave propagation in solids can carry valuable information on mechanical properties and is therefore used to determine Young, E, bulk, K and shear, G moduli which depend on longitudinal and transverse velocity VL and VT respectively. In this context acoustic microscopy can successfully be used in the investigations of porous materials. In micro-analysis, it directly determines the mechanical properties of materials via acoustic signature, V (z); this signature is obtained by recording the change in the reflected acoustic signal with the defocusing distance, z, as the sample is moved towards the acoustic lens. In this work, we simulate the porous alumina (PAl2O3) acoustic signature, V (z), as a function of porosity to evaluate the output signal attenuation at different operating frequencies. We continue our simulation by the determining of the propagating velocities as a function of porosity by the use of the fast Fourier transform (FFT). In a large part of this work, our interest concerns the study of the porous alumina microstructure by calculating the elastic constants. We compare then the obtained values of Young and bulk moduli to the published data given by various ultrasound methods.