Accession Number : ADA318929

Title :   Structural Integrity Analysis and Verification for Aircraft Structures.

Descriptive Note : Final rept. 4 May-31 Sep 95,

Corporate Author : ANALYTICAL SERVICES AND MATERIALS INC HAMPTON VA

Personal Author(s) : Jansen, D. A. ; Boyd, K. L.

PDF Url : ADA318929

Report Date : AUG 1996

Pagination or Media Count : 53

Abstract : The object of this research was to characterize the effects of material age and environmental humidity on fatigue crack growth behavior of 2024-T3, 2024-T4, and 7075-T6 aluminum alloys. These alloys were taken from the fuselage and wing skin of USAF C/KC-135 aircraft representative of the USAF Fleet of C/KC-135 aircraft in age and mission use. The research was broken down into two activities: Experimental testing and data reduction comparison. The test was designed to further the understanding of the effects of humidity on the aluminum alloy's fatigue crack growth rate. The testing performed involved identical test specimen configurations of "aged" material subjected to loading while exposed to two different levels of wet and "dry". These test results were compared to the results of similar test results involving relatively "new" materials to determine if there were any age effects. Of the three materials only A17075-T6 demonstrated humidity effects, and A12024-T3 demonstrated no age effects. The effect of age on fatigue crack growth rates of materials is minimal, while the effects attributed to corrosion appear much more severe.

Descriptors :   *STRUCTURAL ANALYSIS, *AIRFRAMES, TEST AND EVALUATION, ENVIRONMENTS, AIRCRAFT, CORROSION, VERIFICATION, COMPARISON, RATES, ALLOYS, RELIABILITY, CRACK PROPAGATION, CONFIGURATIONS, MISSIONS, DATA REDUCTION, FUSELAGES, TANKER AIRCRAFT, FATIGUE(MECHANICS), WINGS, TRANSPORT AIRCRAFT, HUMIDITY.

Subject Categories : Transport Aircraft
      Structural Engineering and Building Technology

Distribution Statement : APPROVED FOR PUBLIC RELEASE