Vibratory Parameters of Blades From Coordinate Measurement Machine Data

Abstract

This paper deals with the development of a procedure to model geometric variations of blades. Specifically, vibratory parameters of blades are extracted from coordinate measurement machine (CMM) data on an integrally bladed rotor (IBR). The method is based on a proper orthogonal decomposition of CMM data, solid modeling, and finite element techniques. In addition to obtaining natural frequencies and mode shapes of each blade on an IBR, statistics of these modal parameters are also computed and characterized. Numerical results are validated by comparison with experimental results.

Dynamic response characteristics of dual flow-path integrally bladed rotors

“…Here, the mistuned blade frequencies are calculated explicitly from a geometrically perturbed blade with deviations that results in less than a 3percent variation in frequency. The deviations are introduced through perturbations to blade's geometric Principal Component features that quantify small geometrical variations in a blade's geometry [12,30,31]. This is described as a nonproportional mistuning since there are I N I k n O k n total perturbations and are not easily illustrated as with proportional mistuning where blade's frequencies are all perturbed by the same amount.…”

Geometric uncertainties in finite element models of mistuned bladed disks

“…The vector w i of the nodal coordinates of each blade i is then decomposed into a random linear combination of geometric features, with ξ i the vector of the random coefficients of this decomposition. Such decomposition can be obtained for example using a proper orthogonal decomposition of measurement data on blade geometries as presented in [1]. Thus, each diagonal block matrix M 0,i (resp.…”

Novel parametric reduced order model for aeroengine blade dynamics

“…Introduction A bladed disk typically consists of a set of disk/blade sectors that are designed to be identical. However, there are always small variations in the structural properties of individual blades due to manufacturing and assembly tolerances, material imperfections and operational wear and tear [1]. These dimensional and material uncertainties lead to variations of the blade natural frequencies from their nominal design value.…”

“…A consistent body of literature has also been devoted to investigate the effects generated by uncertainties associated to the geometry or material properties on the dynamics of the blade alone [1]. The blade models used in these works are mainly based on high-fidelity FE models, or coordinate measurement machine data [1,23,24].…”

“…The blade models used in these works are mainly based on high-fidelity FE models, or coordinate measurement machine data [1,23,24]. State-of-the-art in ROMs to represent single rotating blades mainly consists in using simple cantilever beams with rectangular cross section to approximate the exact shape by finite element representation [25,26].…”