A new method has been developed for sensitivity calculations of modal characteristics of bladed disks made of anisotropic materials. The method allows the determination of the sensitivity of the natural frequencies and mode shapes of mistuned bladed disks with respect to anisotropy angles that define the crystal orientation of the monocrystalline blades using full-scale finite element models. An enhanced method is proposed to provide high accuracy for the sensitivity analysis of mode shapes. An approach has also been developed for transforming the modal sensitivities to coordinate systems (CS) used in industry for description of the blade anisotropy orientations. The capabilities of the developed methods are demonstrated on examples of a single blade and a mistuned realistic bladed disk finite element models. The modal sensitivity of mistuned bladed disks to anisotropic material orientation is thoroughly studied.

A new method has been developed for the analysis of nonlinear forced response of bladed disks mistuned by blade anisotropy scatter and for the forced response sensitivity to blade material anisotropy orientations. The approach allows for the calculation of bladed disks with nonlinear friction contact interfaces using the multiharmonic balance method. The method uses efficient high-accuracy model reduction method for the minimization of the computational effort while providing required accuracy. The capabilities of the developed methods are validated and demonstrated using a two-blade model. A thorough study of the influence of the material anisotropy mistuning and its sensitivity on the characteristics of the forced response is carried out using finite element (FE) modes of anisotropy mistuned realistic bladed disk with nonlinear friction joints of blade roots and shroud contacts. The dependency of the nonlinear forced response on excitation level and contact pressure values has been carried out for anisotropy mistuned bladed disks.

A new method has been developed for sensitivity calculations of modal characteristics of bladed disks made of anisotropic materials. The method allows the determination of the sensitivity of the natural frequencies and mode shapes of mistuned bladed disks with respect to anisotropy angles that define the crystal orientation of the monocrystalline blades using full-scale finite element models. An enhanced method is proposed to provide high accuracy for the sensitivity analysis of mode shapes. An approach has also been developed for transforming the modal sensitivities to coordinate systems used in industry for description of the blade anisotropy orientations. The capabilities of the developed methods are demonstrated on examples of a single blade and a mistuned realistic bladed disk finite element models. The modal sensitivity of mistuned bladed disks to anisotropic material orientation is thoroughly studied.

A new method has been developed for the analysis of nonlinear forced response of bladed disks mistuned by blade anisotropy scatter and for the forced response sensitivity to blade material anisotropy orientations. The approach allows for the calculation of bladed disks with nonlinear friction contact interfaces using the multi-harmonic balance method. The method uses efficient high-accuracy model reduction method for the minimization of the computational effort while providing required accuracy. The capabilities of the developed methods are validated and demonstrated using a two-blade model. A thorough study of the influence of the material anisotropy mistuning and its sensitivity on the characteristics of the forced response is carried out using finite element modes of anisotropy mistuned realistic bladed disk with nonlinear friction joints of blade roots and shroud contacts. The dependency of the nonlinear forced response on excitation level and contact pressure values has been carried out for anisotropy mistuned bladed disks.

New numerical tools ContaDyn and InterDyn have been developed at University of Sussex for the analysis of nonlinear forced response for tuned and anisotropy mistuned bladed disks with friction contact interfaces. The tools offer capabilities for calculating the nonlinear forced response and its sensitivity with respect to the anisotropy orientation variation of single crystal blades in tuned and mistuned bladed disk assemblies. The calculation method is based on the high-accuracy reduction techniques and the multi-harmonic balance method. A comprehensive validation campaign has been done to validate these numerical capabilities. The calculated nonlinear forced responses are compared with the experimental values obtained for different bladed disk configurations and excitations. The friction contact interfaces at blade roots, blade shrouds and under-platform dampers are considered. For the validation, the measurement data, that were obtained earlier at MTU Aero Engines AG using their rotating test rig, are used. The vibratory measurements were carried out with the contact-less expected time-of-arrival method allowing capturing the vibratory amplitudes for all blades in a mistuned bladed disk assembly. The nonlinear forced response for tuned and anisotropy mis-tuned bladed disks have been calculated for four different resonances and compared with the minimum, maximum and mean values of the measured amplitudes. Moreover, the individual blade forced response levels obtained from measurements and calculations are compared with the maximum amplitude distributions in the mistuned bladed disks. Parametric studies considering the number of harmonics used in the multiharmonic representation of periodic response, the number of mode shapes, the contact stiffness and friction coefficient values have been performed.