Strain Waves in Nonlinear Coaxial Shells Filled with a Viscous Incompressible Fluid

Longitudinal strain waves in physically nonlinear coaxial cylindrical elastic shells containing a viscous incompressible fluid both between and within them are investigated. The influence of the inertia of fluid motion on the wave amplitude and wave velocity is taken into account. If the fluid in the inner shell exerts no effect, the wave velocity and amplitude in the shells do not change. The wave profile in the accompanying coordinate system moves in the negative direction. This means that the motion velocity is subsonic. Accounting for the influence of the inertia of fluid motion in the inner shell leads to a decrease in strain wave velocity, while the viscous stress of the fluid on the shell causes the wave amplitudes to decrease.