Fig. 1. Ultrasonic imaging models. (a) Traditional ultrasonic imaging model; (b) explosion reflection equivalent model

Fig. 2. Schematic diagram of sample structure used in numerical calculation

Fig. 3. Simulated time-domain data. (a) B-scan diagram of model with defect; (b) B-scan diagram of model without defect

Fig. 4. Difference between B-scan diagrams of models with and without defect

Fig. 5. Time domain diagrams obtained by different detections with same excitation. (a) Detection point is at -0.90mm; (b) detection point is at -0.15mm

Fig. 6. PSM calculation results for Fig. 2. (a) Side view of PSM result of shear wave; (b) side view of PSM result of longitudinal wave; (c) front view of PSM result of shear wave; (d) front view of PSM result of longitudinal wave

Fig. 7. Experimental setup

Fig. 8. Experimental B-scan diagram

Fig. 9. PSM reconstructed results for different numbers of frequencies. (a) SNR; (b) calculation time

Fig. 10. PSM results of shear wave for different frequency ranges. (a) Side view of PSM results from 3.1 to 16.9MHz; (b) side view of PSM results from 6.9 to 13.1MHz; (c) front view of PSM results from 3.1 to 16.9MHz; (d) front view of PSM results from 6.9 to 13.1MHz