PSI - Issue 17

Ekaterina M. Zubova et al. / Procedia Structural Integrity 17 (2019) 822–827 Ekaterina M. Zubova et al./ Structural Integrity Procedia 00 (2019) 000 – 000

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5

Energy, V 2 s P, N

Energy, V 2 s

P, N

a

b

Time, s

Time, s

Fig. 5. The energy distribution of all AE signals shown (red line) (a), and the energy distribution of AE signals with selected parameters (blue line) (b).

It should be noted that the registration of AE signals with the selected parameters occurs during the entire test. Each peak at Fig. 5b may indicate the appearance of small cracks in the coating, which appear during the loading of the composite sample. The failure of the coating occurs directly in the zone of destruction of the sample (Fig. 6).

Fig. 6. Photo of failure sample.

In addition, stress – strain curves and strain fields on the surface of the coating were constructed. The stress – strain curves shown points 1-5 for which longitudinal strain fields ε yy are presented (Fig. 7).

σ , MPa

ε , mm/mm

F 5 =16,5 kN

P 1 =5,4 kN

P 2 =8,7 kN

P 3 =11,2 kN

F 3= 12,7 kN

Fig. 7. Fields of longitudinal strain ε yy on the surface of the sample with at appropriate load

Figure 8 shows the distribution of longitudinal strain along the axial line of sample through the geometric center of the sample.