표제지
요약
목차
I. 서론 11
1.1. 연구 배경 및 필요성 11
1.2. 연구 목적 및 내용 16
II. Full Matrix Capture(FMC) 및 Total Focusing Method(TFM)의 기본 원리 18
2.1. 위상배열 초음파탐상검사 기법 20
1) 위상배열 초음파탐상검사 기법의 원리 20
2) 근거리 음장과 집속 24
3) 빔 분산과 굴절각 26
4) 위상배열 초음파탐상검사 기법의 빔 형성 28
2.2. Full Matrix Capture(FMC) 기법 31
2.3. Total Focusing Method(TFM) 기법 32
III. 횡파/종파 웨지와 진동자 수의 변화에 따른 TFM 영상 38
3.1. 개요 38
3.2. 시험편 설계 및 제작 39
3.3. 실험 장치 및 방법 41
3.4. 실험 결과 및 고찰 43
3.5. 소결론 55
IV. 결함 기울기 및 깊이별 횡파/종파 웨지에서의 TFM 모드별 영상 56
4.1. 개요 56
4.2. 시험편 설계 및 제작 57
4.3. 실험 장치 및 방법 60
4.4. 실험 결과 및 고찰 63
4.5. 소결론 95
V. 불용진동자의 발생이 음압손실에 미치는 영향에 대한 고찰 96
5.1. 개요 96
5.2. 시험편 설계 및 제작 97
5.3. 실험 장치 및 방법 98
5.4. 실험 결과 및 고찰 100
(1) 불용진동자 1개 102
(2) 불용진동자 2개 104
(3) 불용진동자 3개 106
(4) 불용진동자 4개 108
(5) 불용진동자 5개 110
5.5. 소결론 113
VI. 결론 116
참고문헌 118
부록 125
Abstract 130
Table 2.1. Beam spread of crystal shapes 26
Table 3.1. Artificial flaw specimens in different depths 39
Table 3.2. Specification of TOPAZ 64 TFM equipment [ZETEC] 41
Table 4.1. Machining length with the angle and depth of EDM flaw specimens 57
Table 5.1. Depth of side drilled holes 97
Table 5.2. Amplitude measured with complete element 101
Table 5.3. Mean value of the amplitude loss rate 101
Table 5.4. Mean value of the amplitude loss rate(1ea dead element) 103
Table 5.5. Mean value of the amplitude loss rate(2ea dead elements) 105
Table 5.6. Mean value of the amplitude loss rate(3ea dead elements) 107
Table 5.7. Mean value of the amplitude loss rate(4ea dead elements) 109
Table 5.8. Mean value of the amplitude loss rate(5ea dead elements) 111
Fig. 1.1. Flow chart of the study 17
Fig. 2.1. Ultrasonic range diagram 19
Fig. 2.2. Ultrasonic propagation based on Snell's law 21
Fig. 2.3. Conventional UT (transmitting) [ZETEC] 22
Fig. 2.4. Conventional UT (receiving) [ZETEC] 23
Fig. 2.5. Phased Array UT (transmitting) [ZETEC] 23
Fig. 2.6. Array element geometries 23
Fig. 2.7. Conventional UT probe vs Phased Array UT probe [ZETEC] 25
Fig. 2.8. Near field zone and pressure variation [28] 25
Fig. 2.9. Phased array probe maximum steering angle 27
Fig. 2.10. Probe and wedge parameters for the focal law 29
Fig. 2.11. Example of phased array beam forming and scan plan 30
Fig. 2.12. FMC data acquisition 31
Fig. 2.13. Image cell reconstruction with the focusing effect 32
Fig. 2.14. Region of interest 33
Fig. 2.15. TFM image reconstruction 33
Fig. 2.16. Multi-mode TFM 37
Fig. 3.1. Artificial flaw specimens 40
Fig. 3.2. TOPAZ 64 TFM [ZETEC] 42
Fig. 3.3. Region of interest 42
Fig. 3.4. TFM images of 0.8 mm, 2.13 mm(30 %) and 4.97 mm(70 %) flaws... 44
Fig. 3.5. TFM images of 0.8 mm, 3.81 mm(30 %) and 8.89 mm(70 %) flaws... 44
Fig. 3.6. TFM images of 0.8 mm, 5.49 mm(30 %) and 12.81 mm(70 %) flaws... 45
Fig. 3.7. TFM images of 0.8 mm, 6.93 mm(30 %) and 16.17 mm(70 %) flaws... 45
Fig. 3.8. TFM images of 0.8 mm, 2.13 mm(30 %) and 4.97 mm(70 %) flaws... 47
Fig. 3.9. TFM images of 0.8 mm, 3.81 mm(30 %) and 8.89 mm(70 %) flaws... 47
Fig. 3.10. TFM images of 0.8 mm, 5.49 mm(30 %) and 12.81 mm(70 %) for... 48
Fig. 3.11. TFM images of 0.8 mm, 6.93 mm(30 %) and 16.17 mm(70 %) flaws... 48
Fig. 3.12. TFM images of 5.49 mm(30 %) flaws in the 18.3 mm thick... 49
Fig. 3.13. 7.1 mm thick specimen(S-wedge) 51
Fig. 3.14. 7.1 mm thick specimen(L-wedge) 51
Fig. 3.15. 12.7 mm thick specimen(S-wedge) 51
Fig. 3.16. 12.7 mm thick specimen(L-wedge) 51
Fig. 3.17. 18.3 mm thick specimen(S-wedge) 52
Fig. 3.18. 18.3 mm thick specimen(L-wedge) 52
Fig. 3.19. 23.1 mm thick specimen(S-wedge) 52
Fig. 3.20. 23.1 mm thick specimen(L-wedge) 52
Fig. 3.21. TFM images of 2.13 mm(30 %) flaws in the 7.1 mm thick specimen... 53
Fig. 4.1. Artificial flaw specimens 58
Fig. 4.2. Photo of the specimens 59
Fig. 4.3. Region of interest(ROI) 60
Fig. 4.4. TT mode of 70°, 9 mm depth flaw using the L-wave wedge 61
Fig. 4.5. Detection method of the Direct Modes (TT, LL) 61
Fig. 4.6. Detection method of the Half-skip Modes (TTT, LLL, LLT) 62
Fig. 4.7. TT mode images for 5 and 9 mm flaws of 70° detected... 64
Fig. 4.8. TT mode images for 5 and 9 mm flaws of 80° detected... 65
Fig. 4.9. TT mode images for 5 and 9 mm flaws of 90° detected... 66
Fig. 4.10. TT mode images for 5 and 9 mm flaws of 100° detected... 67
Fig. 4.11. TT mode images for 5 and 9 mm flaws of 110° detected... 68
Fig. 4.12. LL mode images for 5 and 9 mm flaws of 70° detected... 70
Fig. 4.13. LL mode images for 5 and 9 mm flaws of 80° detected... 71
Fig. 4.14. LL mode images for 5 and 9 mm flaws of 90° detected... 72
Fig. 4.15. LL mode images for 5 and 9 mm flaws of 100° detected... 73
Fig. 4.16. LL mode images for 5 and 9 mm flaws of 110° detected... 74
Fig. 4.17. TTT mode images for 5 and 9 mm flaws of 70° detected... 76
Fig. 4.18. TTT mode images for 5 and 9 mm flaws of 80° detected... 77
Fig. 4.19. TTT mode images for 5 and 9 mm flaws of 90° detected... 78
Fig. 4.20. TTT mode images for 5 and 9 mm flaws of 100° detected... 79
Fig. 4.21. TTT mode images for 5 and 9 mm flaws of 110° detected... 80
Fig. 4.22. LLL modes for 9 mm flaws of each angle... 82
Fig. 4.23. LLL mode images for 5 and 9 mm flaws of 70° detected... 83
Fig. 4.24. LLL mode images for 5 and 9 mm flaws of 80° detected... 84
Fig. 4.25. LLL mode images for 5 and 9 mm flaws of 90° detected... 85
Fig. 4.26. LLL mode images for 5 and 9 mm flaws of 100° detected... 86
Fig. 4.27. LLL mode images for 5 and 9 mm flaws of 110° detected... 87
Fig. 4.28. LLT mode images for 5 and 9 mm flaws of 70° detected... 89
Fig. 4.29. LLT mode images for 5 and 9 mm flaws of 80° detected... 90
Fig. 4.30. LLT mode images for 5 and 9 mm flaws of 90° detected... 91
Fig. 4.31. LLT mode images for 5 and 9 mm flaws of 100° detected... 92
Fig. 4.32. LLT mode images for 5 and 9 mm flaws of 110° detected... 93
Fig. 5.1. Specimen with 5ea side drilled holes (hole diameter : 2 mm) 97
Fig. 5.2. Phased array probe and wedge 98
Fig. 5.3. Switching box 99
Fig. 5.4. Probe setup on the specimen 99
Fig. 5.5. Mean value of the amplitude loss rate 101
Fig. 5.6. Amplitude loss rate of the 1ea deads element 103
Fig. 5.7. Amplitude loss rate of the2ea dead elements 105
Fig. 5.8. Amplitude loss rate of the3ea dead elements 107
Fig. 5.9. Amplitude loss rate of the4ea dead elements 109
Fig. 5.10. Amplitude loss rate of the 5ea dead elements 111
Fig. 5.11. Amplitude loss rate... 114
Fig. 5.12. Amplitude loss rate... 114
Fig. 5.13. Amplitude loss rate... 115
Fig. 5.14. Amplitude loss rate... 115