Accession Number : ADP001912

Title :   Monitoring of Defect Progression by Acoustic Emission,

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

Personal Author(s) : Block,Joachim

Report Date : JUL 1983

Pagination or Media Count : 11

Abstract : Acoustic Emission is a suited technique for the characterization of damage in composite materials, as also in metallic structures. A lot of tests with different CFRP specimens make sure that there are correlations between certain AE parameters, respectively their variation, and characteristics of defects, which are typical for composites. The damage history of the test specimens can be analyzed with a very good chronological resolution. This includes an exact correlation between acoustic and mechanical parameters, such as load, cycle number etc. The present results demonstrate a potential for distinguishing between some dominant failure mechanisms, as fiber failure and matrix cracking, and noise generated by internal friction. Locating existing defects and tracking spatial damage progression is another field of application. All AE data are being monitored continuously in situ- during loading the specimen. Post-test-analysis of the stored data with suited computer programs enables a more sophisticated evaluation.

Descriptors :   *Composite materials, *Failure(Mechanics), *Acoustic emissions, Defects(Materials), Nondestructive testing, Damage assessment, Matrix materials, Loads(Forces), Acoustic data, Mechanical properties

Distribution Statement : APPROVED FOR PUBLIC RELEASE