Characteristics of surface acoustic waves in porous functionally graded materials
An eigenfunction expansion method is carried out to calculate surface acoustic waves (SAWs) propagation in porous functionally graded materials (FGMs) in this article. The properties of the material are assumed to vary continuously across the thickness according to a known variation law. Laguerre polynomial and the relationship between porosity and materials' elastic constants and density are then employed to obtain the SAWs' dispersion curves in iron- based alumina FGMs with different porosity, sample's thickness and material properties' distribution. The effect of porosity, sample's thickness and material properties' distribution on phase velocities of SAWs in porous FGMs are respectively discussed in detail. The conclusion forms theoretical basis for reversing parameters of porous FGMs.