Accession Number : ADA338907

Title :   Development of Structural Integrity Analysis Technologies for Aging Aircraft Structures: Bonded Composite Patch Repair and Weight Function Methods

Descriptive Note : Final rept. Nov 95-Jul 96,

Corporate Author : ANALYTICAL SERVICES AND MATERIALS INC HAMPTON VA

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

PDF Url : ADA338907

Report Date : JUL 1997

Pagination or Media Count : 142

Abstract : The purpose of this research was to develop advanced structural integrity analysis methods for aging aircraft structures. The primary focus of this study was to develop a method for performing fatigue crack growth analyses under a composite (repair patch) on a metallic structure. Also, it was envisioned that these methods would be incorporated into the fatigue crack growth software, AFGROW, so that this promising technology can be transitioned to U.S. Air Force Logistic Centers, U.S. Air Force contractors and other government agencies as quickly as possible. Fatigue cracks growing from fastener holes, or multiple fastener holes, also are common problems found in aging aircraft. To address these problems, analytical methods (weight functions) were developed to assist engineers in the analysis of fatigue cracks growing in arbitrary stress fields, commonly found around cold-worked fastener holes and stop-drilled cracks. Furthermore, an approach to evaluate multiple cracking, or multiple-site damage (MSD), was developed as a future enhancement to the AFGROW program.

Descriptors :   *AIRCRAFT, *STRUCTURAL ANALYSIS, *STRUCTURAL INTEGRITY, COMPUTER PROGRAMS, METALS, AGING(MATERIALS), STRESS ANALYSIS, COMPOSITE MATERIALS, WEIGHTING FUNCTIONS, CRACK PROPAGATION, REPAIR, AIRFRAMES, FATIGUE(MECHANICS), ADHESIVE BONDING.

Subject Categories : Aircraft
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE