Statistical analysis of the forced response of mistuned bladed disks using stochastic reduced basis methods

摘要

This paper is concerned with the forced response statistics of mistuned bladed disk assemblies subjected to a deterministic sinusoidal excitation. A stochastic reduced basis method (SRBM) is used to compute the statistics of the system component amplitudes. In this approach, the system response in the frequency domain is represented using a linear combination of stochastic basis vectors with undermined coefficients. The three terms of the second-order perturbation approximation (which span the stochastic Krylov subspace) are used as basis vectors and the undetermined coefficients areevaluated using stochastic variants of the Bubnov- Galerkin Scheme. This results in explicit expressions for the response quantities in terms of the random system parameters. The statistics of the system response can hence be efficiently computed in the post-processing stage. Numerical results are presented for a model problem to demonstrate that the stochastic reduced basis formulation gives highly accurate results for the response statistical moments.