Research Article

Online Structural Health Monitoring of Rotating Machinery via Ultrasonic Guided Waves

Figure 8

Collected signals of piezoelectric transducers after filtering (a) no. 1, (b) no. 2, (c) no. 3, and (d) no. 4 when the rotor rotates at 15Hz.
(a)
(b)
(c)
(d)