Ultrasonic flaw detection device

• US 5,431,054 A
• Filed: 04/07/1994
• Issued: 07/11/1995
• Est. Priority Date: 04/07/1994
• Status: Expired due to Term

• Current Assignee: Reeves R. Dale, Thomas M. Dehoff
• Original Assignee: Reeves R. Dale, Thomas M. Dehoff
• Inventors: Dehoff, Thomas M., Reeves, R. Dale
• Primary Examiner(s): Noland, Thomas P.
• Assistant Examiner(s): MILLER, ROSE MARY
• Application Number:
  US08/224,262
• Time in Patent Office: 460 Days
• Field of Search: 73/610, 73/612, 73/614, 73/620, 73/622, 73/624, 73/625, 73/628, 73/641
• US Class Current: 73/612
• CPC Class Codes: G01N 2291/0422 Shear waves, transverse waves, horizontally polarised waves
• CPC Class Codes: G01N 2291/0423 Surface waves, e.g. Rayleigh waves, Love waves
• CPC Class Codes: G01N 2291/044 Internal reflections (echoes), e.g. on walls or defects
• CPC Class Codes: G01N 2291/056 Angular incidence, angular propagation
• CPC Class Codes: G01N 2291/103 one emitter, two or more receivers
• CPC Class Codes: G01N 2291/2632 flat
• CPC Class Codes: G01N 29/043 in the interior, e.g. by shear waves
• CPC Class Codes: G01N 29/0645 Display representation or displayed parameters, e.g. A-, B- or C-Scan
• CPC Class Codes: G01N 29/2487 Directing probes, e.g. angle probes directing arrangements G01N29/221
• CPC Class Codes: G01N 29/4463 Signal correction, e.g. distance amplitude correction [DAC], distance gain size [DGS], noise filtering

Abstract

An ultrasonic flaw detection device including a transmitting ultrasonic transducer for producing multiple shear wave skips between inner and outer surfaces of a test object, a plurality of receiving transducers positioned ahead of and parallel to at generally the same incident angle as the transmitting ultrasonic transducer, and a processor electrically connected to the receiving transducers so as to produce a humanly perceivable indication of the reflected energy. The receiving transducers serve to receive energy of the shear wave as reflected from discontinuities in the object. Each of the receiving transducers is electronically isolated from the other receiving transducers. The receiving transducers are connected to a single channel of the processor. A fixture is provided having a first opening for detachably receiving the transmitting ultrasonic transducer and a plurality of receiving openers receiving the receiving transducers therein.

Claims

1. An ultrasonic flaw detection device for detecting flaws in an object comprising:

a transmitting ultrasonic transducer means for producing multiple shear wave skips between inner and outer surfaces of the object;

a plurality of receiving transducer means positioned ahead of and parallel to at generally a same incident angle as said transmitting ultrasonic transducer means, said plurality of receiving transducer means for receiving energy of a shear wave as reflected from discontinuities in the object; and

processing means electrically connected to said plurality of receiving transducer means so as to produce a humanly perceivable indication of a reflected shear wave.

2. The device of claim 1, said transmitting ultrasonic transducer means being larger than each of said receiving transducer means.

3. The device of claim 1, said transmitting ultrasonic transducer means for transmitting shear waves of sufficient energy so as to saturate the object.

4. The device of claim 1, further comprising:

a fixture having means for positioning in proximity to the object, said fixture having a transmitter opening receiving said transmitting ultrasonic transducer means, said fixture having a plurality of receiver openings receiving said plurality of receiving transducer means therein.

5. The device of claim 4, each of said receiver openings being in linear alignment with said transmitter opening, each of said receiver openings having a longitudinal axis in parallel relationship with a longitudinal axis of said transmitter opening.

6. The device of claim 1, further comprising:

a rear receiving transducer positioned behind and parallel to and of generally the same incident angle as said transmitting ultrasonic transducer means, said rear receiving transducer electrically interconnected with said plurality of receiving transducer means and with said processing means.

7. The device of claim 1, each of said plurality of receiving transducer means having a center positioned adjacent exit skip points of the shear wave at one of the surfaces of the test object.

8. The device of claim 1, said plurality of receiving transducer means positioned adjacent the outer surface of the object at exit skip points of the shear wave, the device further comprising:

a second plurality of receiving transducer means positioned adjacent the inner surface of the object, each of said second plurality of receiving transducer means positioned at one-half skip distances of the shear wave.

9. The device of claim 1, each of said plurality of receiving transducer means being electronically isolated from the other receiving transducer means, said plurality of receiving transducer means being connected to a single channel of said processing means.

10. The device of claim 1, said processing means further comprising:

an amplitude correction means electrically connected to said plurality of receiving transducer means, said amplitude correction means for correcting a signal strength of said plurality of receiving transducer means.

11. The device of claim 10, said amplitude correction means comprising:

an amplifier means electrically connected to each of said plurality of receiving transducer means, said amplifier means for amplifying a signal received by said receiving transducer means.

12. The device of claim 1, said plurality of receiving transducer means comprising:

at least three receiver probes affixed in linear alignment and in parallel relationship to said transmitting ultrasonic transducer means.

13. The device of claim 12, said transmitting ultrasonic transducer means comprising:

a transmitter probe having a similar size as each of said receiver probes.

14. The device of claim 12, said transmitting ultrasonic transducer means comprising:

a rectangular transmitter probe array having a longitudinal axis parallel to the shear wave passing into the test object from said array.

15. The device of claim 1, said processing means comprising:

a gating means electrically connected to said plurality of receiving transducer means, said gating means for detecting a signal exceeding a predetermined threshold value.

16. The device of claim 15, said processing means further comprising:

an alarm means electrically connected to said gating means, said alarm means for producing an audio or visual indication relative to said signal.

17. An ultrasonic flaw detection device for detecting flaws in an object comprising:

a transmitting ultrasonic transducer means for producing multiple shear wave skips between inner and outer surfaces of the object;

a plurality of receiving transducer means positioned ahead of and parallel to at generally the same incident angle as said transmitting ultrasonic transducer means, said plurality of receiving transducer means for receiving energy of a shear wave as reflected from discontinuities in the object, each of said plurality of receiving transducer means being electronically isolated from the other of said plurality of receiving transducer means; and

processing means electrically connected to said plurality of receiving transducer means so as to produce a humanly perceivable indication of a reflected shear wave, said plurality of receiving transducer means being connected to a single channel of said processing means.

18. The device of claim 17, further comprising:

a fixture having means for positioning in proximity to the object, said fixture having a transmitter opening detachably receiving said transmitting ultrasonic transducer means, said fixture having a plurality of receiver openings receiving said plurality of receiving transducer means therein.

19. The device of claim 18, each of said receiver openings being in linear alignment with said transmitter opening, each of said receiver openings having a longitudinal axis in parallel relationship with a longitudinal axis of said transmitter opening.