Modelling and analysis of nonlinear vibrations for a coupling hard-coated ring disc-cylindric shell structure under piecewise-continuous coupling conditions

Considering the strain-dependant characteristic of coatings, a unified nonlinear modelling approach is presented for investigating the nonlinear vibration characteristics of a coupling hard-coated ring disc-cylindric shell structure. The piecewise-continuous coupling conditions are proposed and simulated by distributing piecewisecontinuous artificial springs in the circumferential direction of the junction between the shell and disc. According to Sanders' shell theory and the Kirchhoff plate theory, the equations of motion of the coupling hard-coated ring disc-cylindric shell structure are created by the Rayleigh-Ritz method. By employing the multi-segment partitioning strategy, a general approach is proposed for introducing the strain-dependant characteristic into the equations of motion. According to the Newton-Raphson approach, an innovative efficient algorithm is developed for solving the nonlinear equations of motion. The astringency on the number of hard-coated segments is discussed. Comparison investigations are performed to verify the presented method. Further numerical simulations show that the strain-dependant characteristic of coatings induces the soft nonlinear vibration characteristics and contributes to the vibration reduction of structures. Moreover, the damping mechanism of the strain-dependant characteristic is revealed, and the influence of piecewise-continuous coupling conditions on nonlinear vibrations is investigated.