Accession Number : ADP001606

Title :   Damage Tolerance Evaluation of Structures with Small Cracks,

Corporate Author : VEREINIGTE FLUGTECHNISCHE WERKE G M B H BREMEN (GERMANY F R)

Personal Author(s) : Schwarmann,Lueder

Report Date : APR 1983

Pagination or Media Count : 6

Abstract : This paper deals with the analytical determination of the linear-elastic stress intensity factor (SIF) for structures with small cracks. Two different cases are considered : (a) through-the-thickness-cracks emanating from a circular hole, (b) semi-elliptical surface cracks. the analytical methods studied herein are : the WEIGHT- FUNCTION METHOD by GRANDT for the case (a) and the ENGINEERING METHOD by NEWMAN for the case (b). Results obtained from analyses are compared with corresponding test results. The comparisons show good agreement. Analyses show that a cracked pin-loaded hole is the most critical case as compared with other crack-configurations. Furthermore, analyses indicate the degree of conservative assessment when assuming a through-crack instead of a surface crack as far as the crack propagation behaviour is concerned. Both methods studied herein are recommended for practical application in aircraft design.

Descriptors :   *Airframes, *Cracking(Fracturing), *Structural mechanics, Fracture(Mechanics), Crack propagation, Fatigue(Mechanics), Damage assessment, Linearity, Elastic properties, Mathematical analysis

Distribution Statement : APPROVED FOR PUBLIC RELEASE