Patch and methods for monitoring a structure including a patch

• US 9,239,315 B1
• Filed: 06/01/2010
• Issued: 01/19/2016
• Est. Priority Date: 06/01/2010
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Georgeson, Gary E., Bossi, Richard H.
• Primary Examiner(s): Satanovsky, Alexander
• Assistant Examiner(s): RABOVIANSKI, IVAN I
• Application Number:
  US12/791,362
• Time in Patent Office: 2,058 Days
• Field of Search: 702/39, 702/1, 702/35, 702/36, 702/183, 702/187, 702/189
• US Class Current: 1/1
• CPC Class Codes: G01B 5/28 for measuring roughness or irregularity of surfaces
• CPC Class Codes: G01N 2291/0258 Structural degradation, e.g. fatigue of composites, ageing of oils
• CPC Class Codes: G01N 2291/106 one or more transducer arrays
• CPC Class Codes: G01N 29/04 Analysing solids using acoustic emission techniques G01N29/14
• CPC Class Codes: G01N 29/075 by measuring or comparing phase angle measuring frequencies or phase angles per se G01R23/00, G01R25/00
• CPC Class Codes: G01N 29/11 by measuring attenuation of acoustic waves
• CPC Class Codes: G01N 29/2475 Embedded probes, i.e. probes incorporated in objects to be inspected
• CPC Class Codes: G01N 29/262 by electronic orientation or focusing, e.g. with phased arrays phased arrays per se G10K11/34
• CPC Class Codes: G06F 11/30 Monitoring

Abstract

A patch and associated methods for monitoring and inspecting a structure are provided in order to facilitate such inspections. The patch includes a sheet of material configured to be attached to the structure and a frequency steerable array carried by the sheet of material. The frequency steerable array includes a plurality of sources for emitting structural waves in response to an input having a variable frequency such that variations in the frequency of the input cause the structural waves emitted by the plurality of sources to be controllably steered relative to the sheet of material. Methods utilizing one or more frequency steerable arrays for monitoring and inspecting a patch-repaired structure are also provided.

Claims

1. A patch for monitoring a structure for a structural anomaly, the method comprising:

a sheet of material configured to be attached to the structure; and

a frequency steerable array carried by said sheet of material, said frequency steerable array comprising a plurality of sources for emitting structural waves in response to an input having a variable frequency such that variations in the frequency of the input cause a direction in which the structural waves emitted by the plurality of sources propagate to be controllably steered relative to said sheet of material, wherein said frequency steerable array is configured to be responsive to the frequency of the input being swept through a predefined range so as to correspondingly scan the structural waves through a predefined range of angles relative to said sheet of material, and wherein said frequency steerable array is configured to capture the structural waves returning following interaction with the structural anomaly; and

a processor configured to communicate with the frequency steerable array so as;

(i) to confirm an absence of the structural anomaly in an instance in which the structural waves are reflected from an edge of the sheet of material and return to the frequency steerable array and (ii) to detect the structural anomaly in an instance in which the structural anomaly is present and the structural waves are reflected from the structural anomaly in the structure underlying the sheet of material at a location between the frequency steerable array and the edge of the sheet of material and return to the frequency steerable array before a reflection from the edge of the sheet of material.

2. A patch according to claim 1 wherein said frequency steerable array is carried by a central portion of said sheet of material.

3. A patch according to claim 1 wherein said frequency steerable array comprises a single steerable beam transducer comprising a plurality of piezo-electric transceivers.

4. A patch according to claim 1 wherein said frequency steerable array is configured such that the structural waves are controllably steered in 360°

about said sheet of material.

5. A patch according to claim 1 wherein said frequency steerable array is embedded within the sheet of material, and wherein the sheet of material is configured to guide the structural waves emitted by the frequency steerable array.

6. An assembly for monitoring a structure for a structural anomaly, the assembly comprising:

a sheet of material configured to be attached to the structure;

one or more frequency steerable arrays configured to be carried by the sheet of material, each frequency steerable array comprising a plurality of sources for emitting structural waves in response to an input having a variable frequency such that variations in the frequency of the input cause a direction in which the structural waves emitted by the plurality of sources propagate to be controllably steered relative to the structure, wherein at least one frequency steerable array is configured to be responsive to the frequency of the input being swept through a predefined range so as to correspondingly scan the structural waves through a predefined range of angles relative to said sheet of material; and

a processor configured to communicate with the one or more frequency steerable arrays for analyzing a representation of the structural waves that return to the one or more frequency steerable arrays following interaction with the structure in order to identify the structural anomaly, wherein, following emission of structural waves by a respective frequency steerable array of the one or more frequency steerable arrays, the processor is configured;

(i) to confirm an absence of the structural anomaly in an instance in which the structural waves are reflected from an edge of the sheet of material and return to the respective frequency steerable array and (ii) to detect the structural anomaly in an instance in which the structural anomaly is present and the structural waves are reflected from the structural anomaly in the structure underlying the sheet of material at a location between the respective frequency steerable array and the edge of the sheet of material and return to the respective frequency steerable array before a reflection from the edge of the sheet of material.

7. An assembly according to claim 6 wherein said processor is configured to analyze a representation of the structural waves that return to the frequency steerable arrays to identify a characteristic of the structural anomaly.

8. An assembly according to claim 7 wherein the processor is configured to analyze a representation of the structural waves that return to the frequency steerable arrays to identify a size or shape of the structural anomaly.

9. An assembly according to claim 6 wherein each frequency steerable array is configured to capture the structural waves returning following interaction with the structural anomaly.

10. An assembly according to claim 6 wherein each frequency steerable array comprises a single steerable beam transducer comprising a plurality of piezo-electric transceivers.

11. An assembly according to claim 6 wherein each frequency steerable array is configured such that the structural waves are controllably steered in 360°

about said sheet of material.

12. An assembly according to claim 6 wherein the plurality of frequency steerable arrays are embedded within the sheet of material, and wherein the sheet of material is configured to guide the structural waves emitted by the frequency steerable array.

13. A method of monitoring a patch-repaired structure for a structural anomaly, the method comprising:

identifying the structural anomaly;

placing a patch repair with at least one frequency steerable array upon the structure, said frequency steerable array comprising a plurality of sources for emitting structural waves in response to an input having a variable frequency with a direction in which the structural waves propagate being dependent upon the frequency of the input;

providing the input to the sources of the frequency steerable array such that the structural waves emitted by the plurality of sources are controllably steered so as to interact with the structural anomaly, wherein providing the input comprises sweeping the frequency of the input through a predefined range so as to correspondingly scan the structural waves through a predefined range of angles relative to the structure; and

analyzing the structural waves returning following interaction with the structural anomaly to identify a characteristic of the structural anomaly, wherein analyzing the structural waves comprises;

(i) confirming an absence of the structural anomaly in an instance in which the structural waves are reflected from an edge of the patch repair and return to the frequency steerable array and (ii) detecting the structural anomaly in an instance in which the structural anomaly is present and the structural waves are reflected from the structural anomaly in the structure underlying the sheet of material at a location between the frequency steerable array and the edge of the sheet of material and return to the frequency steerable array before a reflection from the edge of the sheet of material.

14. A method according to claim 13 wherein analyzing the structural waves comprises initially capturing a baseline measurement, and wherein providing the input comprises repeatedly providing the input to the sources over time and repeatedly analyzing the structural waves returning following interaction with the structural anomaly in order to identify structural waves that deviate from the baseline measurement.

15. A method according to claim 13 wherein analyzing the structural waves comprises analyzing amplitude, time and phase of the structural waves returning following interaction with the structural anomaly.

16. A method according to claim 13 wherein placing the patch repair having at least one frequency steerable array upon the patch-repaired structure comprises placing the patch repair having a plurality of frequency steerable arrays on the structure so as to overlie the structural anomaly, and wherein analyzing the structural waves comprises analyzing the structural waves returning to each of the plurality of frequency steerable arrays to identify a size or shape of the structural anomaly.

17. A method according to claim 16 wherein providing the input comprises providing the input to the sources of each of the frequency steerable arrays such that some structural waves are reflected from the structural anomaly and return to the frequency steerable array that emitted the structural waves and other structural waves are reflected from the structural anomaly and are directed to another frequency steerable array, different than the frequency steerable array that emitted the structural waves.

18. A method according to claim 13 further comprising fabricating the patch repair by providing a sheet of material, directly writing wiring upon the sheet of material and attaching the frequency steerable array upon the sheet of material so as to be in electrical communication with the wiring.

19. A method according to claim 13 further comprising fabricating the patch repair by providing a sheet of material and directly writing the frequency steerable array upon the sheet of material.