Resonant wave propagation in gun tubes with eccentric bores

Abstract

An analysis of the steady-state vibrations of gun tubes with eccentric bores is performed entirely within the framework of three-dimensional linear elasticity. The dispersion curves for the eccentric cylindrical tube are obtained by satisfying the differential equations and boundary conditions on the external cylindrical surface exactly and the boundary conditions on the eccentric inner cylindrical surface variationally. The resulting solutions clearly exhibit the coupling between the extensional and flexural motions. The forced vibrations are treated by satisfying the continuity conditions at the interface of the moving step in bore pressure using a variational principle in which all conditions, i.e., those of both constraint- and natural-type, appear as natural conditions. The calculations reveal the existence of resonance at critical velocities and increasing coupling to flexural motions with increasing eccentricities.