60
Z. Zhao et al.
Fig. 5.9 The pencil-lead-broken experiment
Many acoustic emission signals generated by structural damage belong to burst
acoustic emission signals. Burst acoustic emission signals are usually simulated by
pencil-lead-broken experiment [6]. Lead breaking signal is the most commonly used
simulated acoustic emission source in acoustic emission detection technology and is
widely representative.
Considering the broken lead experiment easily affected by various factors, such
as the length of the broken lead, direction, the installation of sensors and so on, the
results differ greatly from simulation, but it still can see clearly in the Table 5.1 that
on the premise of localizing speed is not accurate, vertical line method’s deviation
distance is lower than the beamforming’s. Other experiments results are similar.
Table 5.1 Comparison of localizing results with different arrays and methods
Array
Localizing method
X
Y
Deviation distance
1,2
Beamforming
269
302
76.42
2
Beamforming
381
371
70.83
1
Beamforming
348
409
99.05
1,2
Vertical line method
348
261
49.10