Acoustic scattering from functionally graded cylindrical shells

摘要: In this paper, the method of wave function expansion is adopted to study scattering a plane harmonic acoustic incident upon an arbitrarily thick-walled, functionally graded cylindrical shell submerged in and filled with compressible ideal fluids. A laminate approximate model so-called state space formulation conjunction classical transfer matrix (T-matrix) approach, are employed present analytical solution based on three-dimensional exact equations elasticity. Three models, representing elastic properties FGM interlayer considered. all mechanical assumed vary smoothly continuously change volume concentrations constituting materials across thickness shell. first two rule mixture governs. The main difference between them set constants (e.g., Lame’s I Young’s modulus Poisson’s ratio Model II) which governed by mixtures. third model, elegant self-consistent micromechanical assumes interconnected skeletal microstructure region employed. Particular attention paid backscattered response these models wide range frequency for different wall-thicknesses. results reveal technical comparison models. addition, examining various cases (i.e., wall-thicknesses, profiles variations concentration constituents), impact overall constituents also profile variations, resonant investigated. Limiting considered good agreement solutions available literature obtained.