Non-destructive inspection system and associated method

• US 7,367,236 B2
• Filed: 07/21/2005
• Issued: 05/06/2008
• Est. Priority Date: 07/21/2005
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Georgeson, Gary E., Griess, Kenneth H.
• Primary Examiner(s): Lefkowitz; Edward
• Assistant Examiner(s): ROY, PUNAM P
• Application Number:
  US11/186,021
• Publication Number:
  US 20070017297A1
• Time in Patent Office: 1,020 Days
• Field of Search: 738/01, 738/02, 73/121.2, 73/120.9
• US Class Current: 73/801
• CPC Class Codes: G01M 5/0016 of aircraft wings or blades
• CPC Class Codes: G01M 5/0033 by determining damage, crack or wear
• CPC Class Codes: G01N 2291/0231 Composite or layered materials
• CPC Class Codes: G01N 2291/0422 Shear waves, transverse waves, horizontally polarised waves
• CPC Class Codes: G01N 2291/0427 Flexural waves, plate waves, e.g. Lamb waves, tuning fork, cantilever
• CPC Class Codes: G01N 2291/044 Internal reflections (echoes), e.g. on walls or defects
• CPC Class Codes: G01N 2291/106 one or more transducer arrays
• CPC Class Codes: G01N 2291/2694 Wings or other aircraft parts
• CPC Class Codes: G01N 29/045 by imparting shocks to the workpiece and detecting the vibrations or the acoustic waves caused by the shocks measuring resonant frequency G01H13/00; measuring strength properties by application of mechanical stress G01N3/00
• CPC Class Codes: G01N 29/069 Defect imaging, localisation and sizing using, e.g. time of flight diffraction [TOFD], synthetic aperture focusing technique [SAFT], Amplituden-Laufzeit-Ortskurven [ALOK] technique
• CPC Class Codes: G01N 29/2475 Embedded probes, i.e. probes incorporated in objects to be inspected

Abstract

An assembly, system, and method for identifying defects in a structure are provided. The assembly includes a structure of a metallic or composite material, and a flexible sheet of material positioned adjacent to the structure. The assembly also includes a plurality of non-destructive sensors secured to the flexible sheet, and a mechanism operable to impact the flexible sheet or proximate to the flexible sheet to generate stress waves within and along a surface of the structure. The system further provides a data acquisition system capable of communicating with the sensors such that the data acquisition system generates feedback indicative of at least a portion of the structure based on data from the stress waves acquired by the sensors.

Claims

1. A system for identifying defects in a structure comprising:

a flexible sheet of material positioned adjacent to the structure;

a plurality of non-destructive sensors secured to the flexible sheet;

a mechanism operable to externally apply a plurality of impacts onto the flexible sheet and/or onto the structure proximate to the flexible sheet at a plurality of locations to generate stress waves within and along a surface of the structure, wherein the mechanism is operable to externally apply each impact onto the flexible sheet at a different predetermined location and with a predetermined magnitude; and

a data acquisition system capable of communicating with the sensors such that the data acquisition system generates feedback indicative of at least a portion of the structure based on accumulated data from the stress waves acquired by the sensors and further based on the predetermined location and the predetermined magnitude at which each of the plurality of impacts is applied.

2. The system according to claim 1, wherein the flexible sheet of material comprises a non-conductive material.

3. The system according to claim 1, wherein the flexible sheet of material is capable of being secured to the structure using one of a vacuum bag, vacuum frame,

an adhesive backing, and an ultrasonic gel.

4. The system according to claim 1, wherein the sensors comprise piezo-electric sensors.

5. The system according to claim 1, wherein the sensors are arranged about the periphery of the flexible sheet of material.

6. The system according to claim 1, wherein the sensors are arranged in a grid on the flexible sheet of material.

7. The system according to claim 1, wherein the data acquisition system comprises a processor for creating an image including information for detecting a defect in the structure.

8. The system according to claim 1, wherein the mechanism comprises one of a tapper, a tapper having a spring-loaded bar, one or more clickers, and a hammer.

9. The system according to claim 1, wherein the structure comprises one of a metallic and composite material.

10. An assembly for identifying defects comprising:

a structure comprising one of a metallic and composite material;

a flexible sheet of material positioned adjacent to the structure;

a plurality of non-destructive sensors secured to the flexible sheet; and

a mechanism operable to externally apply a plurality of impacts onto the flexible sheet and/or onto the structure proximate to the flexible sheet to generate stress waves within and along a surface of the structure, wherein the mechanism is operable to apply each of the plurality of impacts at a different predetermined location and with a predetermined magnitude.

11. The assembly according to claim 10, wherein the flexible sheet of material comprises a non-conductive material.

12. The assembly according to claim 11, wherein the flexible sheet of material comprises a polymeric material.

13. The assembly according to claim 10, wherein the flexible sheet of material is capable of being secured to the structure using one of a vacuum bag, vacuum frame,

an adhesive backing, and an ultrasonic gel.

14. The assembly according to claim 10, wherein the sensors comprise piezo-electric sensors.

15. The assembly according to claim 10, wherein the sensors are arranged about the periphery of the flexible sheet of material.

16. The assembly according to claim 10, wherein the sensors are arranged in a grid about the flexible sheet of material.

17. The assembly according to claim 10, wherein the mechanism comprises one of a tapper, a tapper having a spring-loaded bar, one or more clickers, and a hammer.

18. A method for identifying defects in a structure utilizing a plurality of non-destructive sensors secured to a flexible sheet of material, the method comprising:

positioning the flexible sheet of material adjacent to the structure;

applying a plurality of external impacts onto the flexible sheet and/or onto the structure proximate to the flexible sheet, wherein each of the plurality of impacts is applied at a different predetermined location and with a predetermined magnitude to generate stress waves within and along a surface of the structure; and

detecting the stress waves with the sensors and deriving data from the stress waves that is indicative of at least a portion of the structure and that is based on accumulated data derived from the stress waves and the predetermined location and the predetermined magnitude at which each of the plurality of impacts is applied.

19. The method according to claim 18, further comprising securing the flexible sheet of material to the structure using one of a vacuum bag, vacuum frame, an adhesive backing, and an ultrasonic gel.

20. The method according to claim 18, wherein applying comprises impacting the flexible sheet of material with one of a tapper, a tapper having a spring-loaded bar, one or more clickers, and a hammer.

21. The method according to claim 18, wherein applying comprises impacting the flexible sheet of material and structure one of manually and automatically.

22. The method according to claim 18, wherein applying comprises impacting about the periphery of the flexible sheet of material.

23. The method according to claim 18, wherein applying comprises impacting the flexible sheet of material in a predetermined pattern.

24. The method according to claim 18, further comprising communicating the data acquired by the sensors to a data acquisition system and creating an image of at least a portion of the structure with the data acquisition system based on the data acquired by the sensors.

25. A system for identifying defects in an aircraft structure comprising:

an aircraft comprising substantially composite material;

an impact-echo assembly for externally applying a plurality of impacts onto the aircraft, wherein each of the plurality of impacts is applied with a predetermined magnitude and at a different predetermined location to generate stress waves within and along a surface of the aircraft; and

a data acquisition system capable of communicating with the impact-echo assembly such that the data acquisition system generates feedback indicative of at least a portion of the aircraft based on accumulated data from the impact-echo assembly and further based on the predetermined location and magnitude at which each force of the plurality of impacts is applied.

26. The system according to claim 25, wherein the impact-echo assembly comprises:

a flexible sheet of material positioned adjacent to the aircraft;

a plurality of non-destructive sensors secured to the flexible sheet; and

a mechanism operable to impact the flexible sheet or proximate to the flexible sheet to generate the stress waves.

27. The system according to claim 25, wherein the data acquisition system creates an image comprising information for detecting a defect in the aircraft.