Journal of Failure Analysis and Prevention

, Volume 14, Issue 1, pp 21–26 | Cite as

Thermal and Mechanical Failure Analysis of a Two-Stroke Motocross Engine Piston

  • Dev Sharma
  • Abdulaziz Ali
  • Mohammad Alabdullah
  • Marwan A. Alnajjar
  • Matthew T. Siniawski
Case History---Peer-Reviewed


The failure analysis of an aluminum two-stroke single-cylinder 250 cc motocross engine piston with significant material cracking was performed using both computational and theoretical approaches revealing several contributing factors to the cracking. A main central crack in the piston skirt is the direct result of mechanical fatigue imposed by the contact loads exerted on the piston during cold-start situations. Two symmetric secondary cracks also observed on the piston skirt region are similarly caused by the resulting contact of the piston skirt against the engine cylinder wall. Although thermal fatigue is considered, theoretical calculations dismiss the likelihood that thermal stresses develop as a result of the piston-cylinder wall contact under normal operating conditions. However, under extreme temperatures due to cold start or altered air/fuel ratios, thermal fatigue plays a more likely role. A finite element analysis confirms the critical stress locations resulting from the contact of the piston skirt against the engine cylinder wall, and analyses of the fracture surfaces confirm the initiation and propagation of the fatigue cracks.


Piston failure Fatigue analysis Cracking Fracture surface Scuffing 


  1. 1.
    Y. Kligerman, I. Etsion, A. Shinkarenko, Improving tribological performance of piston rings by partial surface texturing. Trans. ASME 127, 632–638 (2005)Google Scholar
  2. 2.
    F.S. Silva, Fatigue on engine pistons—a compendium of case studies. Eng. Fail. Anal. 13, 480–492 (2006)CrossRefGoogle Scholar
  3. 3.
    A.K. Agarwal, Biofuels (alcohols and biodiesel) applications as fuels for internal combustion engines. Prog. Energy Combust. Sci. 33, 233–271 (2007)CrossRefGoogle Scholar
  4. 4.
    R. Mikalsen, A.P. Roskilly, The design and simulation of a two-stroke free-piston compression ignition engine for electrical power generation. Appl. Therm. Eng. 28, 589–600 (2008)CrossRefGoogle Scholar
  5. 5.
    T.T. Mon, R. Mamat, N. Kamsah, Member, IAENG, Thermal Analysis of SI-Engine using Simplified Finite Element Model. Proceedings of the World Congress on Engineering, vol 3, (2011)Google Scholar
  6. 6.
    V. Esfahanian, A. Javaheri, M. Ghaffarpour, Thermal analysis of an SI engine piston using different combustion boundary condition treatments. Appl. Therm. Eng. 26, 277–287 (2006)CrossRefGoogle Scholar
  7. 7.
    G.R. Halford, and S.S. Manson, Life prediction of thermal mechanical fatigue using strainrange partitioning. Therm. Fatigue Mater. Compon. 239–254 (1976)Google Scholar
  8. 8.
    A.N. Towo, M.P. Ansell, Fatigue evaluation and dynamic mechanical thermal analysis of sisal fibre–thermosetting resin composites. Compos. Sci. Technol. 68, 925–932 (2008)CrossRefGoogle Scholar
  9. 9.
    G.P. Zhang, C.A. Volkert, R. Schwaiger, R. Mönig, O. Kraft, Fatigue and thermal fatigue damage analysis of thin metal films. Microelectron. Reliab. 47, 2007–2013 (2007)CrossRefGoogle Scholar
  10. 10.
    Metals Handbook, Volume 2—Properties and Selection: Nonferrous Alloys and Special-Purpose Materials. ASM International 10th Edn. (1990)Google Scholar

Copyright information

© ASM International 2013

Authors and Affiliations

  • Dev Sharma
    • 1
  • Abdulaziz Ali
    • 1
  • Mohammad Alabdullah
    • 1
  • Marwan A. Alnajjar
    • 1
  • Matthew T. Siniawski
    • 1
  1. 1.Department of Mechanical EngineeringLoyola Marymount UniversityLos AngelesUSA

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