Thermoelastic damping in cylindrical shells with arbitrary boundaries

An effective method is proposed for the dynamic modelling and thermoelastic damping (TED) evaluation of the cylindrical shells with arbitrary boundaries. The arbitrary boundary conditions of the cylindrical shell are simulated by a set of springs, and the degree of the boundary condition is achieved by adjusting the spring stiffnesses. Hamilton's principle with the Rayleigh-Ritz method is employed to establish the equation of motion of the cylindrical shell, and the natural frequencies of the cylindrical shell with arbitrary boundaries are obtained by solving the eigenvalue problem of the equation of motion. An analytical model for the TED in the cylindrical shell is obtained by computing the dissipated energy and the maximum elastic potential energy in the cylindrical shell. The correctness and feasibility of the present theoretical model are verified by comparing the natural frequencies and TED obtained by this analytical method with those from the published literature and the finite element method (FEM). The convergence analysis of the analytical expression of TED is carried out. The influences of geometrical parameters and different types of spring stiffnesses on the TED are studied. In addition, the effects of the boundary conditions and the vibration modes of the structure on the TED characteristics of the cylindrical shells with arbitrary boundaries are analyzed. The present model provides theoretical reference for optimizing the cylindrical shell resonators with high quality factors.