J Mater Sci Technol ›› 2005, Vol. 21 ›› Issue (06): 856-862.

• Research Articles • Previous Articles     Next Articles

Improved Fatigue and Damage Tolerant Material Design for Aerospace Industry

Yigeng XU, Jiang CHEN, Jianmin LI, Zefei ZHU   

  1. School of Aerospace, Automotive and Design Engineering, University of Hertfordshire, Hatfield, Herts, AL10 9AB, UK
  • Received:2005-06-20 Revised:1900-01-01 Online:2005-11-28 Published:2009-10-10
  • Contact: Yigeng XU

Abstract: Various micro-mechanical and micro-structural influences on fatigue crack growth resistance of the material have been investigated over the years. It is widely recognized that resistance to fatigue crack growth can be differentiated into `intrinsic' and `extrinsic'. The separation of intrinsic and extrinsic crack growth resistance has constituted a major theme of fatigue research in the last 30 years, with the concept of crack closure or crack tip shielding being used to rationalize a wide range of micro-structural and mechanical influences on fatigue crack growth behavior. An accurately quantitative understanding of intrinsic and extrinsic effects on crack growth is essential to directed alloy design for improved fatigue resistance, and/or improved structural service life. This paper presents a compliance-based crack closure measurement method and a multi-mechanism based analytical model for the separation of intrinsic and extrinsic material fatigue resistance, with application in characterizing the fatigue performance of two high strength damage tolerant airframe Al alloys.

Key words: Fatigue, Crack closure, Alloy design