Nonlinear vibration analysis of double cylindrical shells coupled structure with bolted connection and partially attached constrained layer damping

Abstract

To effectively implement constrained layer damping (CLD) for vibration reduction of connected cylindrical shell structure, it is necessary to establish a dynamic model of the composite cylindrical shell to guide vibration reduction design. The nonlinear vibration behavior of bolted double cylindrical shells with partially attached CLD under base excitation is studied by semi-analytical method. Based on Lagrange energy equation and Donnell's thin shell theory, the dynamic equation of double cylindrical shell is established. The orthogonal polynomial is introduced as the displacement admissible function, and the continuous variable stiffness elastic constraint is employed to simulate the bottom boundary conditions. The influence of CLD materials on structural vibration is ingeniously introduced into the nonlinear model of bolts, and the equivalent stiffness and equivalent damping of bolts are obtained by Fourier series expansion to accurately describe the nonlinear behavior of bolted connections. In addition, the incremental harmonic balance method is adopted to solve the nonlinear equations. Then the rationality of the semi-analytical model of bolted double cylindrical shells with CLD is verified by constructing an experimental test system, comparing it with ANSYS simulation and references. Finally, the nonlinear vibration behavior of bolted double cylindrical shells with partially attached CLD under different excitation levels, connection stiffness and damping thickness values (including viscoelastic layer and constrained layer) are investigated.