Introduction to ultrasonic testing

1. Kein Folientitel

Introduction to
Ultrasonic Testing
SD 218
© Michael Berke
Agfa NDT GmbH, Hürth, Germany
1994 - 2002
Krautkramer NDT Ultrasonic Systems

2. Straight beam probe

housing
socket
dampingblock
matchingelement
crystal
protecting face
(probe delay)
workpiece
Sound pulse
Krautkramer NDT Ultrasonic Systems

3. Angle beam probe

damping blocks
housing
socket
perspex wedge
(probe delay)
workpiece
crystal
Sound pulse
Krautkramer NDT Ultrasonic Systems

4. Sound field

3
Sound field
N = near field length
near field
far field
= angle of divergence
acoustical axis (central beam)
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5. Flaw detection

Krautkramer NDT Ultrasonic Systems

6. Flaw detection

10
Krautkramer NDT Ultrasonic Systems
20
30
40

7. Flaw detection

10
20
30
Krautkramer NDT Ultrasonic Systems
40

8. Bad flaw orientation

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9. Improper flaw location

crack
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10. Angle reflection

10
crack
Krautkramer NDT Ultrasonic Systems
20
30
40

11. Angle reflection

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12. Vertical, near surface flaw

10
Krautkramer NDT Ultrasonic Systems
20
30
40

13. Tandem technique (top)

a1
T
5 10
5 10
15
Krautkramer NDT Ultrasonic Systems
15
R

14. Tandem technique (middle)

a2
T
5 10
15
5 10
Krautkramer NDT Ultrasonic Systems
15
R

15. Tandem technique (bottom)

a3
T
5 10
15
5 10
15
Krautkramer NDT Ultrasonic Systems
R

16. Improper flaw orientation

10
Krautkramer NDT Ultrasonic Systems
20
30
40

17. Perfect flaw orientation

10
20
30
40
Krautkramer NDT Ultrasonic Systems

18. Flaw detectability with improper flaw orientation

reflected sound waves
5 10
15
sound beam
flat defect
Krautkramer NDT Ultrasonic Systems

19. Flaw distance

s
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20. Principle of transit time measurement

finish signal
(echo)
transmitter
start signal
(pulse)
Stopwatch
probe
transit time
measurement
sound transit
path
work piece
Krautkramer NDT Ultrasonic Systems

21. CRT / A-scan display

0
2
4
6
8
Krautkramer NDT Ultrasonic Systems
10

22. Priciple, transmission pulse

transmitter
transmission
pulse
sound wave starts at crystal
work piece
probe
light point
0
2
4
6
8
Krautkramer NDT Ultrasonic Systems
10

23. Priciple, sound wave in the workpiece

transmitter
sound wave
work piece
probe
0
2
4
6
8
Krautkramer NDT Ultrasonic Systems
10

24. Priciple, sound pulse at the back wall

transmitter
work piece
probe
0
2
4
6
8
Krautkramer NDT Ultrasonic Systems
10

25. Priciple, sound pulse at the coupling surface

transmitter
work piece
probe
0
2
4
6
8
Krautkramer NDT Ultrasonic Systems
10

26. Priciple, echo display and 2nd run

transmitter
work piece
probe
back wall
echo
0
2
4
6
8
Krautkramer NDT Ultrasonic Systems
10

27. Probe delay

2
electrical
zero
(initial pulse)
4
6
mechanical
zero
(surface)
crystal
probe
protecting face
Krautkramer NDT Ultrasonic Systems
8
10

28. Probe delay

electical
zero
(initial pulse)
0
probe
2
delay
(wedge)
sound wave
work piece
Krautkramer NDT Ultrasonic Systems
4
6
8
10
mechanical
zero
(surface)

29. Flaw location and echo display

flaw
work piece
probe
back wall
echo
flaw
echo
0
2
4
6
8
10
Krautkramer NDT Ultrasonic Systems

30. Flaw location and echo display

flaw
work piece
probe
back wall
echo
flaw
echo
0
2
4
6
8
10
Krautkramer NDT Ultrasonic Systems

31. Flaw location and echo display

flaw
work piece
probe
flaw
echo
0
2
4
back wall
echo
6
8
10
Krautkramer NDT Ultrasonic Systems

32. Flaw location and echo display

flaw
work piece
probe
back wall
echo
flaw echo
covered
by initial
pulse
0
2
4
6
8
Krautkramer NDT Ultrasonic Systems
10

33. Flaw location and echo display

flaw
work piece
probe
back wall
echo:
without
with flaw
0
2
4
6
8
Krautkramer NDT Ultrasonic Systems
10

34. Flaw location and echo display

flaw
work piece
probe
flaw echo
sequence
0
2
4
6
8
Krautkramer NDT Ultrasonic Systems
10

35. Dead zone

dead zone
0
2
4
Krautkramer NDT Ultrasonic Systems
6
8
10

36. Longitudinal wave

wave length
direction of
osscillation
direction of propagation
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37. Transverse wave

wave length
direction of
osscillation
direction of propagation
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38. Relection and refraction

L
L
reflected
wave
incident
wave
L
medium 1
medium 2
refracted
wave
L
Krautkramer NDT Ultrasonic Systems
L

39. Angle beam probe with both wave types

10
20
30
40
L
T
possible flaw
locations
0
2
4
6
8
10
Krautkramer NDT Ultrasonic Systems

40. Longitudinal surface wave

L
reflected
wave
incident
wave
perspex
steel
= 1 = 27.5°
T = 33.3°
L = 90°
L
L
T
refracted
waves
T
Krautkramer NDT Ultrasonic Systems

41. 45° transverse wave in steel

L
reflected
wave
incident
wave
perspex
steel
refracted
transverse wave
T
= 36.4°
T = 45°
Krautkramer NDT Ultrasonic Systems
T

42. Transverse surface wave

L
reflected
wave
incident
wave
surface
wave
perspex
steel
T
= 2 = 57°
T = 90°
Krautkramer NDT Ultrasonic Systems
O

43. Total reflection

L
reflected
wave
incident
wave
perspex
steel
total reflection
> 57°
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44. Ranges for incident waves

27,5°
L
57°
perspex
90°
steel
T
33,3°
Krautkramer NDT Ultrasonic Systems

45. Near surface detectability with angle beam pobes

10
Krautkramer NDT Ultrasonic Systems
20

46. TR-probe / dual crystal probe

transmitter
socket
acoustical
barrier
receiver
socket
damping blocks
crystal
delay
Krautkramer NDT Ultrasonic Systems

47. Probe delay with TR-probes

BE
IP
0
2
4
TR-probe
work piece
Krautkramer NDT Ultrasonic Systems
6
8
10

48. Cross talk at high gain

BE
IP
flaw
echo
cross talk
echo
0
2
4
TR-probe
6
8
flaw
Krautkramer NDT Ultrasonic Systems
10

49. Range calibration

0
0
2
4
6
50
8
10
div.
100 mm
steel, L
Krautkramer NDT Ultrasonic Systems

50. Calibration block 1 with angle beam probes

5
10
15
70°
60°
45°
Krautkramer NDT Ultrasonic Systems

51. 1st echo from circular section

5
10
15
0
2
4
100 mm
Krautkramer NDT Ultrasonic Systems
6
8
10

52. Echo sequence from 100 mm radius

5
10
15
0
2
4
6
8
10
100 mm 200 mm 300 mm
Krautkramer NDT Ultrasonic Systems

53. 25 mm radius of calibration block 2

this wave will be
absorbed !
s 1 = 25 mm
s 2 = 100 mm
s 3 = 175 mm
etc.
Krautkramer NDT Ultrasonic Systems

54. 50 mm radius of calibration block 2

s 1 = 50 mm
s 2 = 125 mm
s 3 = 200 mm
etc.
Krautkramer NDT Ultrasonic Systems

55. 100 mm range calibration on K2

5
10
15
0
0
Krautkramer NDT Ultrasonic Systems
2
4
6
8
10
100 mm
steel

56. Flaw loaction

s = sound path
k = scale factor
R = screen reading
s = k•R
0
15
10
5
s
work piece
reflector
Krautkramer NDT Ultrasonic Systems
2
4
6
8
10

57. Flaw location with angle beam probes

projection
point
Sound entry point
"flaw triangle"
a
ß
d
s
ß = probe angle
s = sound path
a = surface distance
d = depth
a = s•sin ß
d = s•cos ß
ß
Krautkramer NDT Ultrasonic Systems
flaw location

58. Flaw location with angle beam probes

x
15
10
a = surface distance
a' = reduced surface distance
x = x-value = distance:
index point front edge of probe
a
a'
5
s
work piece
d
reflector
Krautkramer NDT Ultrasonic Systems

59. Flaw location with an angle beam probe on a plate

a
15
T
10
5
s
d = apparent depth
apparent flaw location
Krautkramer NDT Ultrasonic Systems

60. Flaw location with an angle beam probe on a plate

d' = apparent depth
d = real depth
T = work piece thickness
a = s • sin
d‘ = s • cos
d = 2T - d
a
15
T
10
5
s
d
real flaw location
d'
apparent flaw location
Krautkramer NDT Ultrasonic Systems

61. Large defects parallel to the scanning surface

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62. Scanning the edge of the defect

Flaw echo drops to 50% of
its maximum value
Krautkramer NDT Ultrasonic Systems

63. Determination of the defect area

probe position
with echo amplitude
reduced to 50 %
delamination
"half value" positions
Krautkramer NDT Ultrasonic Systems

64. Flaw sizes and echo amplitudes

R
IP
0
2
4
6
BE
8
10
R
IP
0
2
4
6
BE
8
10
Krautkramer NDT Ultrasonic Systems
R
IP
0
2
4
6
BE
8
10

65. Flaw distances and echo amplitudes

IP
0
R
2
BE
4
IP
0
6
R
2
4
Krautkramer NDT Ultrasonic Systems
10
BE
6
IP
0
8
8
10
R BE
2
4
6
8
10

66. Distance amplitude curves on the CRT screen

B4S
BE
F
0
100
200
300
400
500
Krautkramer NDT Ultrasonic Systems

67. Defect evaluation by comparison - 1

instrument gain: G = 34 dB
F
IP
BE
80 %
F
0
2
4
Krautkramer NDT Ultrasonic Systems
6
8
10

68. Defect evaluation by comparison - 2

R
IP
0
instrument gain:
2
34 dB
Krautkramer NDT Ultrasonic Systems
4
6
BE
8
10

69. Defect evaluation by comparison - 3

RE BE
IP
+ 8 dB
0
instrument gain:
2
42 dB
Krautkramer NDT Ultrasonic Systems
4
6
8
10

70. Distance amplitude curve (DAC)

Echo
Position
1
10
20
30
2
40
10
20
3
30
40
10
20
1
2
3
4
4
30
40
10
20
30
40
0
Krautkramer NDT Ultrasonic Systems
2
4
6
8
10

71. DAC and TCG

time corrected gain
DAC
0
2
4
6
8
10
0
2
Krautkramer NDT Ultrasonic Systems
4
6
8
10

72. Kein Folientitel

Krautkramer NDT Ultrasonic Systems