Coupled vibration of an annular plate-cylindrical drum structure with material-nonlinearity damping patches considering position-mistuned and stiffness-mistuned connections

Considering position-mistuned and stiffness-mistuned connections, the coupled vibration of an annular plate-cylindrical drum structure with material-nonlinearity damping patches is studied. These two mistuned connections are inevitable, but they are seldom concerned in published works. Moreover, the mistuned connections can cause local excessive vibrations, so vibration suppression is in demand. Spraying hard coatings with material nonlinearity is a good damping method. Their damping-related and stiffness-related parameters will change with strain, which will improve the vibration-reduction ability but bring obstacles to modelling. This paper focuses on the consideration of both mistuned connections and material-nonlinearity damping patches (MDP) and presents a general modeling method of connection-mistuned annular plate-cylindrical drum structures with MDP. Position-mistuned and stiffness-mistuned connections are emulated by developing the spring approach, and dynamic equations are created by combining Sanders’ shell theory, Kirchhoff’s plate theory, and Lagrange equation. Furthermore, the region decomposition approach is developed for considering the material nonlinearity, and an efficient solution is provided to solve the corresponding nonlinear complex equations. The study is adequately validated. Finally, numerical results indicate that mistuned connections cause the local-vibration behavior, frequency separation, and coupled vibration between substructures and modes. Moreover, mistuned connections also seriously affect the response curves and response cloud charts.