Critical velocities and displacements of anisotropic tubes under a moving pressure

Abstract

Critical velocities and middle-surface displacements of anisotropic axisymmetric cylindrical shells (tubes) under a uniform internal pressure moving at a constant velocity are derived in closed-form expressions by using the Love–Kirchhoff thin shell theory incorporating the rotary inertia and material anisotropy. The formulation is based on the general three-dimensional constitutive relations for orthotropic elastic materials and provides a unified treatment of orthotropic, transversely isotropic, cubic and isotropic tubes, which can represent various composite and metallic tubes. Closed-form formulas are first obtained for the general case with both the rotary inertia and radial stress effects, which are then reduced to the special cases without the rotary inertia effect and/or radial stress effect. It is shown that when the rotary inertia effect is suppressed and the radial normal stress is neglected, the newly derived formulas for the critical velocities of orthotropic and isotropic tubes recover the two existing ones for thin tubes as special cases. An example for an isotropic tube is provided to illustrate the new formulas, which give the values of the critical velocity and dynamic amplification factor that agree well with those obtained experimentally and computationally by others.