A Method for Reduced-Order Modelling of Mistuned Bladed Disks

The aim of this paper is to present a strategy for the prediction of the dynamic response of mistuned bladed disks by adopting a numerical model simple enough to be used at the early design stages. The computational model has been constructed following four steps: (1) the models for the blade and the corresponding disk sector have been first created on the basis of the beam theory, being the disk sector a simple frame; (2) one single bladed disk sector has been then updated so as to match the modal properties of a “high-fidelity” (HF) 3D Finite Element (FE) reference model, after imposing cyclic symmetry conditions on both models; (3) the full disk surrogate model has been obtained by extension and the blades assembled according to a Component Mode Synthesis (CMS) strategy; (4) a random mistuning has been finally introduced in the model through the modification of the blades before the assemblage. Different modelling strategies are investigated considering an academic disk model having the geometric proportions of a large axial compressor stage.