Damage Detection of Closed Crack in a Metallic Plate Using Nonlinear Ultrasonic Time Reversal Method

Figure 4

Experimental waves in Lamb wave time reversal procedure for the path P7–16: (a) forward wave after 424 mm (50 V excitation), (b) forward wave after 424 mm (150 V excitation), (c) reconstructed wave (50 V excitation), and (d) reconstructed wave (150 V excitation).

(a)

(b)

(c)

(d)