Computational Geometrically Nonlinear Vibration Analysis of Uncertain Mistuned Bladed Disks

The recent improvements in turbomachinery design requires the analysis of exceptional operating regime of bladed disks corresponding to geometrical nonlinear effects induced by the large displacements/deformations. In addition, the random nature of the mistuning has also to be modeled. First, a mean nonlinear reduced-order model of the tuned bladed disk is explicitly constructed in the context of the finite element method. The investigation is then devoted to the modeling of the mistuning through the nonparametric probabilistic approach extended to the nonlinear geometric context. The stochastic nonlinear equations are solved in the time domain using the Monte Carlo numerical simulation coupled with advanced arc-length methods adapted to high nonlinear response levels. Finally, the methodology is applied through a numerical example of a bladed disk and a nonlinear analysis is performed in both time and frequency domain.