A New Technique for Helicopter Rotor Blade Service Life Substantiation / K. B. Amer, R. J. Sullivan, J. D. Eakin
- Conference Author:
- Structural Fatigue in Aircraft (1965 : Seattle, Wash.)
- Physical Description:
- 1 online resource (19 pages) : illustrations, figures, tables
- Additional Creators:
- Amer, K. B., Eakin, J. D., Sullivan, R. J., American Society for Testing and Materials, and ASTM International
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- A technique is described whereby helicopter rotor blade service life can be substantiated by combining laboratory fatigue tests with cyclic loading applied during conventional ground endurance tests of rotor control and power-transmission systems. The method for applying cyclic loading involves the use of excitation panels, which consist of an array of stationary panels properly spaced and located close beneath the rotor to excite a natural flapwise bending mode. During the investigation, blade cyclic moments were excited that were ten per cent higher than the maximum cyclic bending moment measured in flight on the same rotor blade. The level of fatigue loading could be controlled by adjusting the vertical distance between the panels and rotor. The more rapid application of load (third-mode excitation at nine per revolution instead of the conventional one-per-revolution occurrence of peak inflight loads), coupled with sustained application of damage (100 per cent of the time for panels instead of approximately 16 per cent of the time for a normal flight spectrum), permits the excitation panels to impose damage approximately 56 times faster than experienced in flight. Tests are now being conducted to determine generalized design rules for application of excitation panels to rotors of any number of blades of any size.
- Dates of Publication and/or Sequential Designation:
- Volume 1966, Issue 404 (January 1966)
- Other Subject(s):
- Digital File Characteristics:
- text file PDF
- Bibliography Note:
- Includes bibliographical references.
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- Reproduction Note:
- Electronic reproduction. W. Conshohocken, Pa. : ASTM International, 1966. Mode of access: World Wide Web. System requirements: Web browser. Access may be restricted to users at subscribing institutions.
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- Mode of access: World Wide Web.
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- ASTM International PDF Purchase price USD25.
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