On the Determination of a Scatter Factor for Fatigue Lives Based on the Lead Crack Concept

Authors

  • Adriano F. Siqueira Universidade de São Paulo/ Escola de Engenharia de Lorena
  • Carlos Antonio Reis Pereira Baptista Universidade de São Paulo/ Escola de Engenharia de Lorena
  • Loris Molent Universidade de São Paulo/ Escola de Engenharia de Lorena Visiting fellow

Keywords:

fatigue crack propagation, aluminum alloys, scatter factor, airframe.

Abstract

http://dx.doi.org/10.5028/jatm.v5i2.219

The lead crack concept is adopted as the basis for a new fatigue lifing method using the safe life philosophy. As part of its management strategy, a full-scale fatigue test is conducted to identify high-risk locations in the airframe, and for each item the time for retirement or structural repair is dictated by the safe life limit. A scatter factor is defined to account for the scatter in the material fatigue performance. The fatigue life variation of any given region of aircraft metallic structures is assumed to primarily correlate to the distribution of the equivalent pre-crack size of the fatigue crack initiators. By assuming that the sizes of these crack initiators are independent from each other, the present paper estimates the scatter factor by calculating safe life limit based on known growth characteristics of critical cracks.

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Published

2013-06-01

Issue

Vol. 5 No. 2 (2013): APR./JUN. 2013

Section

Original Papers

License

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