Accession Number : ADP001919

Title :   Behaviour of Idealized Discontinuities and Impact Damages in CFRP under Fatigue Loading,

Corporate Author : DEUTSCHE FORSCHUNGS- UND VERSUCHSANSTALT FUER LUFT- UND RAUMFAHRT E V STUTTGART (GERMANY F R)

Personal Author(s) : Aoki,R. M.

Report Date : JUL 1983

Pagination or Media Count : 10

Abstract : Current results of an ongoing experimental program concerning the behaviour of impact damaged CFRP specimens are presented. The purpose of this ongoing research program is to determine the characteristics resulting from localized low-energy impact damage and also the behaviour of the damaged specimens under harmonic fatigue loading. Damage simulating a dropped medium weight (300 g) tool was introduced by drop weights with various geometry impactors. Also circular defects were built into specimens as idealized discontinuities. The damage propagation under static and fatigue loading (R = 0.1, R = -1) was monitored using NDI methods consisting of US-C-scan, temperature measurements and acoustic emission. The basic parameters of this investigation included the influence of stacking sequence and impactor tip radius, as well as the degree of local discontinuity in the outer layers of the specimens. The straight sided specimens with quasi-isotropic lay-up (0/45/90)s are manufactured from T300/Code 69. The feasibility of simulating impact damages with this form of built-in idealized discontinuities is shown.

Descriptors :   *Carbon reinforced composites, *Impact strength, *Fatigue(Mechanics), Loads(Forces), Damage assessment, Structural mechanics, Fatigue tests(Mechanics), Strength(Mechanics), Performance(Engineering)

Distribution Statement : APPROVED FOR PUBLIC RELEASE