Acoustic wave propagation in functionally graded material (FGM) cylinders

We present a numerical method for calculating the guided wave propagation in Functionally Graded Material (FGM) cylinders. The FGM cylinder made up of stainless steel and silicon nitride is described. The method uses the wave equation with the elastic moduli and mass density assumed to be functions of position. We developed the necessary formulas to calculate the dispersion curves in FGM cylinders of various geometries. The radial variation laws of Young’s modulus, Poisson’s ratio and mass density are given. The position-dependent stiffness constants are deduced. The equations of motion are solved by expanding each mechanical displacement component using Legendre polynomials and harmonic functions. The dispersion curves for axisymmetric modes are presented.