Journal of Failure Analysis and Prevention

, Volume 7, Issue 5, pp 311–315 | Cite as

Fracture Mode Transition in a Mild Steel Due to Change in Loading Condition

  • N. Ejaz
  • I. N. Qureshi
  • I. Salam
Case History


A tripod jack collapsed when hoisting an aircraft being overhauled. The load capacity of the jack was 30 ton, and the cause of failure was corrosion in the weld region of a leg extension. During breakdown, a spacer in the tripod jack assembly also failed as the result of secondary damage. The failed spacer joins six braces in the assembly of jack. Material of the spacer was mild steel (AISI 1005). Failure of the leg extension imparted an imbalance on the underload structure of the jack. The spacer initially deformed and fractured partly by dimpled rupture and finally failed in a brittle, transgranular manner due to change in loading condition as the jack collapsed catastrophically.


Fracture modes Aircraft Transgranular fracture Tensile tearing 


  1. 1.
    Properties and selection; iron and steels, Metals handbook, 9th edn., vol. 1, American Society for Metals, Metals Park, OH 125,163,129 (1978)Google Scholar
  2. 2.
    Stahlschlusel 2005, Key to Steels, Alloys data base on CD ROMGoogle Scholar
  3. 3.
    Ross, R.D.: Metallic materials, Specification handbook, John Wiley & Sons, NY, p. 204 (1972)Google Scholar
  4. 4.
    Metallography and microstructure, Metals handbook, 9th edn., vol. 9, American Society for Metals, Metals Park, OH, 231–236 (1985)Google Scholar
  5. 5.
    Fractography, Metals handbook, 9th edn., vol. 12, ASM International, Materials Park, OH, 12–15 (1987)Google Scholar
  6. 6.
    Kiessling, R., with collaboration of Lang, N.: Non-metallic inclusions in steels, Part I–IV, Institute of Materials, London, 117–127 (1997)Google Scholar
  7. 7.
    Colangelo, V.I., Heiser, F.A.: Analysis of metallurgical failures, 2nd edn., John Wiley & Sons, NY, p. 118 (1987)Google Scholar

Copyright information

© ASM International 2007

Authors and Affiliations

  1. 1.Metallurgy DivisionRawalpindiPakistan

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