Failure analysis of a high-speed pinion shaft
The failure of a high-speed pinion shaft from a marine diesel engine was investigated. The shaft, which had been in service for more than 30 years, failed shortly after a service operation in which the bearings were replaced. Examination of the shaft revealed cyclic fatigue as the failure mechanism, with a substantial distribution of nonmetallic inclusions near the fracture initiation site. Fracture mechanics analysis indicated that the inclusions would be unlikely to have served as failure initiation sites if only stresses acting on the shaft were induced by normal service loads. Further examination of the bearing elements revealed an abnormal wear pattern, consistent with the application of elevated bending loads to the shaft after bearing replacement. The root cause of failure was determined to be an increase in service stresses after bearing replacement along with the presence of significant nonmetallic inclusions in the pinion shaft.
Keywordsfatigue fatigue crack growth analysis fracture mechanics in failure analysis shaft failure
Unable to display preview. Download preview PDF.
- 1.H. Chandler: Heat Treater’s Guide: Practices and Procedures for Irons and Steels, 2nd ed., ASM International, Materials Park, OH, 1995.Google Scholar
- 2.R.W. Hertzberg: Deformation and Fracture Mechanics of Engineering Materials, 4th ed., John Wiley & Sons, Inc., New York, NY, 1995.Google Scholar
- 3.R.C. Bates and W.G. Clark: “Fractography and Fracture Mechanics,” Trans. Am. Soc. Met., June 1969, 62, pp. 380–89.Google Scholar
- 4.R.L. Boring, G.M. Davidson, A. Hammel, S.D. Henry, S.R. Lampman, F. Reidenback, and W.W. Scott, Jr., ed.: Fatigue and Fracture, vol. 19, ASM Handbook, ASM International, Materials Park, OH, 1996.Google Scholar
- 5.G.R. Irwin, P.C. Paris, and H. Tada: The Stress Analysis of Cracks Handbook, 3rd ed., The American Society of Mechanical Engineers, New York, NY, 2000.Google Scholar
- 6.H.E. Boyer, ed.: Atlas of Fatigue Curves, American Society for Metals, Metals Park, OH, 1986.Google Scholar
- 7.S. Cunningham, S. Fawaz, J.A. Harter, A. Litvinov, D. Newman, and H.R. Wu: “AFGROW Material Database,” version 4.0009e.12, downloadable computer software, United States Air Force, 2004.Google Scholar
- 8.N.E. Dowling: Mechanical Behavior of Materials: Engineering Methods for Deformation, Fracture, and Fatigue, 2nd ed., Prentice Hall, Upper Saddle River, NJ, 1999.Google Scholar