PSI - Issue 18

845 3

Ekaterina M. Zubova et al. / Procedia Structural Integrity 18 (2019) 843–848 Zubova et al./ Structural Integrity Procedia 00 (2019) 000–000

1 – Instron 5885 system 2 – Vic-3D system 3 – Specimen

1

AE Sensors

3

2

a

b

Fig. 2. Experimental set-up with a combined use of the testing and registration equipment (a); location of AE sensors on specimen surface (b).

3. Results and discussions 3.1. The results of mechanical tests and signal processing AE During the mechanical tests for all groups of samples the maximum values of the load were determined. The averaged values for ten samples are presented in table 1.

Table 1. The average value of the maximum load.

The average value of the maximum load for ten samples, kN

Samples group

Type 1 Type 2 Type 3 Type 4

64, 3 41,3 19,7 20,8

AE data registration was carried out using a special hardware option that allows squaring and signal integration, as a result of which the signal energy parameter value can be obtained. In this case, the energy parameter is calculated in energy units ( , 1 = 10 −14 V 2 s ) [AMSY-6 Handbook]. During the analysis of the experimental data obtained for each sample, diagrams of the dependence of the energy parameter of AE signals on the load were plotted (Fig. 3). For each group of samples at an initial loading stage the values of loads corresponding to the primary formations of damage in CFRP were determined using the AE technique. The load occurring at initial emission of AE was determined from the diagram of energy parameter AE signals dependence on the load [Bourchak et al. (2013)] (Fig. 3).