On some regularities in dynamic response of cyclic periodic structures
The paper deals with cyclic periodic structures modelling the bladed disk assemblies with friction elements for vibration damping. These elements placed between adiacent blades reduce the vibration amplitudes by means of dry friction resulting from centrifugal forces acting on the elements and relative displacements of blades. However, the application of these friction elements results in an additional dynamical coupling, which together with mistuning of some system parameters (e.g. blade eigenfrequency or contact parameters) can cause a localization of vibration. Here the authors investigate a linear approximation of such a system. The structure composed of cyclic periodic cells modelled each as clamped-free beam and interacting with each other by means of viscoelastic elements of complex stiffness is considered for dynamic system analysis. In the case of free vibrations as well as in the case of steady-state dynamic response to a harmonic pressure load, the authors study a perfect periodic structure and the structures with periodically mistured parameters (blade eigenfrequencies and contact parameters). Some regularities in the dynamic response of the systems with mistuning have been noticed. Despite the fact that only a linear approximation has been used, the results and conclusions can be applied to models with describe the blade interaction in a nonlinear way.
scientific article; zbMATH DE number 1487110