Wave scattering by infinite cylindrical shell structures submerged in a fluid medium

This work analyzes the wave scattering by an elastic, fluid-filled, cylindrical shell structure submerged in a fluid medium and subjected to the effect of a point pressure load placed inside or outside the cylindrical shell. The shell structures modeled have constant cross-sections along their axis, corresponding to 2.5D problems. A Fourier transformation in the direction in which the geometry does not vary is applied to find the 3D field as the summation of the 2D solutions for different spatial wavenumbers. The wave propagation patterns are analyzed for shell structures defined by two concentric or non-concentric cylindrical circular surfaces. The boundary element method, formulated in the frequency domain, is used to calculate the dynamic response of these systems when the shell is defined by non-concentric cylindrical circular surfaces, while analytical solutions are used to compute the response when two concentric cylindrical circular surfaces define the shell structure. Different simulations are performed for receivers placed at distinct positions, in order to study the normal modes excited at each load position within each shell structure type. Both frequency and time solutions are obtained, in an attempt to obtain wave propagation features that may be used as a basis for developing non-destructive testing techniques