Tensile load, acoustic emission

The development of damage in the form of matrix cracks within 1-D CMCs subject to tensile loading has been traced by direct optical observations on specimens with carefully polished surfaces, and by acoustic emission detection,7 9 62,79-81 as well as by ultrasonic velocity measurements.82 Interrupted tests, in conjunction with sectioning and SEM observations, have also been used. Analysis of the matrix damage found in 1-D CMCs provides the... 

Acoustic Emission of Polymers under Tensile Load... 

The tensile tests have been accompanied by acoustic emission (AE) registration, fuU-field surface strain-mapping (SM), progressive crack imaging at different load levels and micrographic inspection of the cross-sections of samples. The results of testing have been reported in [108,109]. 

As specified above, the lifetimes under these types of loadings ate rather long which makes it hard to realize tests on laboratory equipment. This kind of studies needs to be done with a limited number of tests, thus the use of different techniques to monitor the damage in real lime is mandatory. Acoustic emission (AE) appears to be a good candidate in this case. It consists of recording transient elastic waves on the material created by damage mechanisms. There are several studies referring to this kind of method for different types of CMCs under tensile... 

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