Carnegie Mellon University

Blade Diagnostics Corporation

Siemens Energy, Inc.

Blade Diagnostic Corporation

Drew M Feiner

Jerry Howard Griffin

Daniel J Ryan

Alex J Kowalski

Michael J Cushman

Blair E Echols

Roger W Heinig

A method and apparatus for maintaining integrally bladed rotors (IBR) includes using first vibration data from a IBR vibration apparatus of a first IBR to determine a set of values for a corresponding set of inherent vibratory properties based on a reduced order model for an IBR type to which the first IBR belongs. Shape data indicating an initial shape of a surface of a first blade is used, with repair data that indicates a candidate repair to form a restored shape, to determine a change in a value of an inherent blade section vibratory property of the set of inherent vibratory properties. A condition of the first IBR is determined based at least in part on the change in the value of the inherent blade section vibratory property. The first IBR is maintained based on the condition.

Techniques for automated maintenance of integrally bladed rotors

A reduced order model of an integrally bladed turbine disk (IBD) is used with experimental vibrational test data to modify a finite element model (FEM) of the IBD so that the FEM more accurately predicts the vibrational mistuning of the disk. The refined FEM can be used to evaluate a proposed modification of the IBD before the hardware is actually modified, and to evaluate the actual modification if there is a difference between the proposed and actual modifications.

Refinement of finite element model of integrally bladed disk

A method and system for establishing sets of blade frequency values for each rotating blade of a rotor assembly at two or more different points in time and determining an indication of blade health from the change in the blade frequency values is provided. Blade frequency values are determined by receiving measurements of vibratory responses from blade monitoring equipment () and processing via a processing device () vibration data as a system of rotating blades to extract a frequency of each blade. Sets of blade frequency values are compared to determine a change in the blade frequency values for each rotating blade to provide the indication of blade health.

Method and system for monitoring rotating blade health

A reduced order model called the Fundamental Mistuning Model (FMM) accurately predicts vibratory response of a bladed disk system. The FMM software may describe the normal modes and natural frequencies of a mistuned bladed disk using only its tuned system frequencies and the frequency mistuning of each blade/disk sector (i.e., the sector frequencies). The FMM system identification methods&#x2014;basic and advanced FMM ID methods&#x2014;use the normal (i.e., mistuned) modes and natural frequencies of the mistuned bladed disk to determine sector frequencies as well as tuned system frequencies. FMM may predict how much the bladed disk will vibrate under the operating (rotating) conditions. Field calibration and testing of the blades may be performed using traveling wave analysis and FMM ID methods. The FMM model can be generated completely from experimental data. Because of FMM's simplicity, no special interfaces are required for FMM to be compatible with a finite element model. Because of the rules governing abstracts, this abstract should not be used to construe the claims.

Fundamental mistuning model for determining system properties and predicting vibratory response of bladed disks

An extended version of a reduced order model called the Fundamental Mistuning Model (FMM) accurately predicts vibratory response and damping in a bladed disk system. The extended FMM software may describe the normal modes and natural frequencies of a mistuned bladed disk as well as damping in the disk using complex-valued inputs of its tuned system frequencies and the frequency mistuning of each blade/disk sector (i.e., the sector frequencies). The extended FMM system identification methods&#x2014;basic and advanced extended FMM ID methods&#x2014;also use complex mistuned modes and complex frequencies of the mistuned bladed disk as inputs. As a result, in extended FMM ID calculations, the tuned system frequencies and the mistuning frequency ratios are complex numbers. The real parts of frequencies relate to sector frequencies as well as tuned system frequencies. However, the imaginary part can be related to system damping. Thus, extended FMM ID methodology may be used to identify not only the frequencies of the individual sectors of the bladed disk, but also to identify damping in the bladed disk system. The extended FMM may predict how much the bladed disk will vibrate under the operating (rotating) conditions. Field calibration and testing of the blades may be performed using traveling wave analysis and extended FMM ID methods. The extended FMM model can be generated completely from experimental data. Because of extended FMM's simplicity, no special interfaces are required for extended FMM to be compatible with a finite element model. Because of the rules governing abstracts, this abstract should not be used to construe the claims.

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Pittsburgh, PA, United States of America

Drew M Feiner