Standard Practice for Developing Simplified Fatigue Load Spectra

Importancia y uso:

4.1 This standard practice provides one means for determining fatigue load spectra for aeroplane durability assessments. This information can be used in conjunction with Specification F3115/F3115M, Section 5, Load Considerations.

4.1.1 Users of this practice may propose alternate spectra, subject to the approval of their CAA.

4.2 The methods are applicable to the durability evaluation of wings of small aeroplanes. Additional calculation (such as methods noted in ACE-100-01) are needed to properly develop load spectra for fatigue evaluation of empennage and/or configurations with canards (or forward wings) and/or winglets (or tip fins), fuselage, and potentially other components, with approval from appropriate regulatory agency.

4.3 Much of the material presented herein is directly taken from AC 23-13A. The FAA developed the flight load spectra, presented herein, based on a statistical analysis of the data presented in DOT/FAA/CT-91/20. The ground load spectra are directly from AFS-120-73-2.

4.4 The flight load spectra, presented in Section 7, includes an adjustment (1.5 standard deviations) to the average measured load frequency. The adjustment accounts for the variability in the loading spectra experienced by individual aeroplanes, as well as across aeroplane types. The magnitude of the adjustment was selected to maintain the probability that a component will reach its safe-life without a detectable fatigue crack established by scatter factor (see paragraph 2–15 of AC 23-13A).

Subcomité:

F44.30

Referida por:

F3651_F3651M-23, F3264-24

Volúmen:

15.09

Número ICS:

49.035 (Components for aerospace construction)

Palabras clave:

airframe structure; fatigue; fatigue spectra; gust; load; maneuver; spectra; taxi ;