Article Article
Health Monitoring of a Rotating Disk Using a Combined Analytical-Experimental Approach

Rotating disks undergo rigorous mechanical loading conditions that make them subject to a variety of failure mechanisms leading to structural deformities and cracking. During operation, periodic loading fluctuations and other related factors cause fractures and hidden internal cracks that can only be detected via noninvasive types of health monitoring and/or nondestructive testing. This testing goes further to examine material discontinuities and other irregularities that have grown to become critical defects that can lead to failure. Hence, the objective of this work is to conduct a collective analytical and experimental study to present a wellrounded structural assessment of a rotating disk by means of a health monitoring approach and to appraise the capabilities of an in-house rotor spin system. The analyses utilized the finite element method to analyze the disk with and without an induced crack at different loading levels, such as rotational speeds starting at 3000 up to 10 000 rpm. A parallel experiment was conducted to spin the disk at the desired speeds in an attempt to correlate the experimental findings with the analytical results. The testing involved conducting spin experiments, which covered the rotor in both damaged and undamaged (notched and unnotched) states. Damaged disks had artificially induced through-thickness anomalies represented in the web region ranging from 25.4 to 50.8 mm in length. This study aims to identify anomalies that are greater than 12.7 mm, applying available means of structural health monitoring and nondestructive testing, and documenting failure mechanisms experienced by the rotor system under typical turbine engine operating conditions.

References
Abdul-Aziz, Ali, “Nondestructive Testing of Ceramic Materials,” Materials Evaluation, Vol. 64, 2006, pp. 20–22. Abdul-Aziz, Ali, Jeffrey J. Trudell and George Y. Baakilini, “Finite Element Design Study of a Bladed, Flat Rotating Disk to Simulate Cracking in a Typical Turbine Disk,” Proceedings of SPIE, Vol. 5767, 2005, pp. 298–307. Abdul-Aziz, Ali, Jeffrey J. Trudell and George Y. Baakilini, “Finite Element Design Study of a Bladed, Flat Rotating Disk to Simulate Cracking in a Typical Turbine Disk: Part II,” Proceedings of SPIE, Vol. 6176, 2006, pp. 61760J.1–61760J.9. Bently, Don, “Detecting Cracked Shafts at Earlier Levels,” Orbit, Vol. 2, July 1982, pp. 1–11. Drumm, M.J., “Nondestructive, Real-Time Measurement of Cracks in Jet Engine Rotors,” www.testdevices.com, 1998. Gyekenyesi, Andrew L., Jerzy T. Sawicki and George Y. Baaklini, Vibration Based Crack Detection in a Rotating Disk. Part 1 – An Analytical Study, NASA/TM – 2003-212624/Part 1, 2003. Gyekenyesi, Andrew L., Jerzy T. Sawicki, Richard E. Martin, Wayne C. Haase and George Baaklini, Vibration Based Crack Detection in a Rotating Disk. Part 2 – Experimental Results, NASA/TM – 2005-212624/Part 2, 2005. Holt, John M. (Tim), Harold Mindlin and C.Y. Ho, Structural Alloys Handbook, West Lafayette, Indiana, Cindas/Purdue University, 1996. Sekhar, A.S. and B.S. Prabhu, “Condition Monitoring of Cracked Rotors through Transient Response,” Mechanism and Machine Theory, Vol. 33, 1998, pp. 1167–1175. Simon, Donald L., An Overview of the NASA Aviation Safety Program Propulsion Health Monitoring Element, NASA/TM – 2000-210348 (AIAA– 2000–3624), 2000. Sonnichsen, E., “Real-Time Detection of Developing Cracks in Jet Engine Rotors,” IEEE, 0–7803–5846–5/00, 2000. Wauer, Jorg, “On the Dynamics of Cracked Rotors: A Literature Survey,” Applied Mechanics Reviews, Vol. 43, 1990, pp. 13–17.
Metrics
Usage Shares
Total Views
64 Page Views
Total Shares
0 Tweets
64
0 PDF Downloads
0
0 Facebook Shares
Total Usage
64