Journal of Failure Analysis and Prevention

, Volume 12, Issue 3, pp 286–294 | Cite as

Failure Analysis of a Cracked Gasoline Engine Cylinder Head

  • M. Azadi
  • A. Mafi
  • M. Roozban
  • F. Moghaddam
Technical Article---Peer-Reviewed


This article presents a failure analysis on a gasoline engine cylinder head made of aluminum alloy, which has been used in passenger cars. During an endurance test, a crack initiated from the interior wall of a hole in the center of the cylinder head and then propagated through the thickness of the cylinder head. The metallurgical examinations are conducted in the crack origin zone. The results show that there are many casting pores due to poor quality of casting in the failed cylinder head which has certainly played a crucial role in initiating the crack. Finite element analysis of the cylinder head is performed to identify the stress components. Modeling of a bolt for the hole shows that the plastic stresses are occurred. Moreover, the lower strength of the material due to high assembly stress caused the failure in the cylinder head.


Cylinder head Crack Failure analysis FEM Fatigue SEM Fractography 



The authors thank the IPCo., including the laboratory, the CAE, and the design departments for the financial supports in experiments, especially Mr. Sharghi, Mr. Hosseini, Mr. Abaszadeh, Mr. Salimi, and Mr. Asadi.


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Copyright information

© ASM International 2012

Authors and Affiliations

  1. 1.School of Mechanical EngineeringSharif University of TechnologyTehranIran
  2. 2.Fatigue Workgroup, Vehicle/Engine Laboratory and Validation DepartmentIrankhodro Powertrain Company (IPCo.)TehranIran
  3. 3.Mechanical Testing and Materials LaboratoryIrankhodro Powertrain Company (IPCo.)TehranIran
  4. 4.CAE DepartmentIrankhodro Powertrain Company (IPCo.)TehranIran

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