Abstract
This paper represents further development of Modified Modal
Domain Analysis (MMDA) (Sinha, 2009), which is a breakthrough
method for the reduced-order modeling of a bladed rotor with
geometric mistuning. The bases vectors for model reduction in
MMDA have been formed using the mode shapes of cyclic sectors
with blades’ geometries perturbed along the POD (Proper
Orthogonal Decomposition) features. The use of mode shapes from
modal analyses of cyclic sectors perturbed along the POD features
adds an additional step of creating the finite element models of
artificially perturbed geometries. Here, an alternative formulation
of MMDA is presented in which bases vectors are created from
cyclic sectors with actual blades. Therefore, the additional step of
creating artificial blades with geometries perturbed along POD
features is avoided.
The MMDA is also extended to a bladed rotor in which a few
blades have extremely large mistuning; for example, blended
airfoils. The validity of proposed approaches is shown by
comparing with ANSYS results for full (360 degree) bladed rotor.
