Mistuning phenomenon has been studied extensively for almost half a century, especially for bladed disk assemblies. However, the studies hitherto focus on either linear models with distributed parameter mistuning or nonlinear models with point mistuning. The former method is not realistic under significant non-linear effects. Whereas the latter method lacks accuracy since discrete mistuning elements distort the mode shapes unless their numbers are large. Therefore a model which includes both nonlinearities and distributed parameter mistuning is required. In this study, a formulation for the analysis of mistuned bladed disk assemblies under periodic loads in the presence of distributed parameter mistuning and nonlinearity is given. The proposed method combines the component mode synthesis based reduced order modeling approach with non-linear forced response analysis technique in modal space. The calculations are carried out in modal domain which reduces the computational effort considerably, especially for large size finite element (FE) models. The mistuning is imposed on individual blade natural frequencies, which is more realistic compared to adding discrete mistuning elements. A case study is presented to demonstrate the application of the method and the effect of macro-slip friction type nonlinearity on the dynamic analysis of a mistuned bladed disk assembly. It is concluded that considering non-linear effects in the dynamic analysis of mistuned bladed disks is crucial when there exists significant non-linearity, such as gaps and friction dampers in the system. It is believed that this is the first study in which non-linear dynamic analysis of bladed disk assemblies is carried out with distributed parameter mistuning.
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