6 Correlation Analysis of Acoustic Emission Signals …
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0
50
100
150
200
250
300
350
400
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
Distance(mm)
Correlation Cofficient
Correlation Cofficient of Acoustic Emission
0
50
100
150
200
250
300
350
400
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
Distance(mm)
Correlation Cofficient
Correlation Cofficient of Acoustic Emission
0
50
100
150
200
250
300
350
400
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
Distance(mm)
Correlation Cofficient
Correlation Cofficient of Acoustic Emission
0
50
100
150
200
250
300
350
400
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
Distance(mm)
Correlation Cofficient
Correlation Cofficient of Acoustic Emission
Fig. 6.3 Correlation coefficients for measuring points
curve climax, which means the little similarity between the others of these signals.
The correlation coefficients give the fluctuation trend and attenuate with the increase
of propagation distances.
6.5 Relation Between Correlation Coefficient and Signal
Wave Feature
Relations between correlation coefficients and signal wave features are analyzed in
order to find out the reasons for the correlation coefficient fluctuations. Table 6.2
lists the correlation coefficients between the signal at 50 mm from impact damage
point and at other gauges. Form Table 6.2, the coefficient 0.7158 means some linear
Table 6.2 Correlation coefficients for AE signals at 50 mm position and other gauges
Distance (mm) 50 55
60
65
140
150
160
170
Coefficients
1
0.7158 0.4772 0.1895 0.1909 0.2369 0.2016 0.1161