About Free Boundary and Interfacial Vibrations of Thin Elastic Semi-Infinite Circular Cylindrical Shells

Free boundary and interfacial vibrations of closed and nonclosed semiinfinite cylindrical shells composed of finite and semiinfinite orthotropic thin cylindrical shells with different elastic properties are studied. Using the system of equations of the related classical theory of orthotropic cylindrical shells, dispersion equations and asymptotic formulas for obtaining eigenfrequencies of possible boundary and interfacial vibrations of composed cylindrical shells are derived. An algorithm for separating possible boundary and interfacial vibrations is presented. An asymptotic link is established between the dispersion equations of problems in hand and analogous problems for semiinfinite composed plate and platestrip, respectively. By examples of shells with different lengs of finite cylindrical shells approximate values of dimensionless characteristics of eigenfrequencies and attenuating characteristics of the related vibration forms are given