Accession Number : ADA337794

Title :   Verification and Baseline Fatigue Crack Growth Data of Ti-6-4, 430-195ksi Steel, and 7075-T73

Descriptive Note : Final rept. 1 Jan-30 Sep 95

Corporate Author : ANALYTICAL SERVICES AND MATERIALS INC HAMPTON VA

Personal Author(s) : Elsner, J. H. ; Boyd, K. L. ; Krishnan, S. ; Harter, J. A.

PDF Url : ADA337794

Report Date : MAR 1997

Pagination or Media Count : 38

Abstract : This research included baseline crack growth data for Ti-6-4 and 4340-195ksi steel, verification testing of the Ti-6-4 data, testing various geometries, and AFGROW development Baseline test data were produced for Ti-6-4 and 4340-195ksi. Center crack specimens were tested at four stress ratios. Load shedding enabled crack growth rates as low as 10.0(exp -9) to be recorded for both materials. Determining crack growth rates at this level is important for life predictions, since much of the life is accounted for when cracks are small. Open hole Ti-6-4 specimens were tested to verify the crack growth rate data generated and to test AFGROW's predictive abilities. For the six open hole specimens, AFGROW had an average error of 12%. Joint specimen also tested in order to verify AFGROW's abilities. These specimens were modeled with finite element analysis to determine the load transfer around the rivet holes. Once this was accomplished, predictions were run and compared to test data. The results of the single, multiple in-line joint, and multiple staggered joint specimens were good.

Descriptors :   *VERIFICATION, *STEEL, *CRACK PROPAGATION, *BASE LINES, *FATIGUE(MECHANICS), *TITANIUM ALLOYS, TEST AND EVALUATION, STRESSES, DATA BASES, EXPERIMENTAL DATA, AIRCRAFT, FINITE ELEMENT ANALYSIS, CRACKS, HOLES(OPENINGS), RIVETS, TRANSFER.

Subject Categories : Properties of Metals and Alloys
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE