NONDESTRUCTIVE INSPECTION OF AIRCRAFT STIFFENERS

• US 20090205429A1
• Filed: 02/15/2008
• Published: 08/20/2009
• Est. Priority Date: 02/15/2008
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Georgeson, Gary E., Bommer, Jason Philip, Lewis, Dennis M.
• Granted Patent: US 8,499,631 B2
• Time in Patent Office: Days
• US Class Current: 73/634
• CPC Class Codes: G01M 5/0091 by using electromagnetic excitation or detection

Abstract

Nondestructive inspection of a plurality of aircraft hat stiffeners includes exciting cavities of the stiffeners with electromagnetic radiation, and analyzing electromagnetic field responses of the cavities to detect state changes of the stiffeners.

Claims

1. A method comprising performing nondestructive inspection of a plurality of stiffeners in an aircraft, the nondestructive inspection including exciting cavities of the stiffeners with electromagnetic radiation;

and analyzing electromagnetic field responses of the cavities to detect state changes of the stiffeners.

2. The method of claim 1, wherein exciting each cavity includes supplying excitation at one location of each stiffener;

and wherein the analyzing each cavity includes measuring the cavity response at another location of each stiffener.

3. The method of claim 2, wherein each stiffener is excited to exhibit characteristics of an electromagnetic waveguide.

4. The method of claim 2, wherein each stiffener is excited to exhibit characteristics of a cavity resonator.

5. The method of claim 1, wherein detecting a state change includes measuring a cavity response and comparing the measured response to baseline data.

6. The method of claim 1, wherein the stiffeners are inspected for delamination.

7. The method of claim 1, wherein the stiffeners are inspected for fluid ingress.

8. The method of claim 1, wherein the nondestructive inspection is performed on hat stiffeners as a matter of routine.

9. The method of claim 1, wherein the nondestructive inspection is performed only on those stiffeners having a greater likelihood of a state change.

10. The method of claim 9, wherein those stiffeners having a greater likelihood of a state change include stiffeners below galleys and lavatories of the aircraft.

11. The method of claim 9, wherein those stiffeners having a greater likelihood of a state change include stiffeners around cargo bay doors of the aircraft.

12. The method of claim 1, wherein a handheld device is used to supply excitation to the cavities and also to analyze the measured cavity responses.

13. A method comprising performing routine nondestructive inspection on hat stiffeners of an aircraft, the method comprising:

supplying an electromagnetic excitation to cavities of the hat stiffeners; and

analyzing measured cavity responses of the hat stiffeners to detect any state changes of the hat stiffeners.

14. The method of claim 13, wherein the electromagnetic excitation is supplied only to those hat stiffeners having a greater likelihood of a state change.

15. The method of claim 14, further comprising supplying an electromagnetic excitation to other structures having cavities with electromagnetic properties;

and measuring the cavity responses of the other structures to detect state changes of the other structures.

16. The method of claim 13, wherein a handheld device is used to supply excitation to the cavities and also to analyze the measured cavity responses.

18. The aircraft of claim 16, further comprising an analyzer for analyzing measured responses of the cavities to detect state changes of the hat stiffeners.

17. An aircraft comprising a plurality of composite hat stiffeners, each hat stiffener having a transmit antenna at one location for exciting its stiffener cavity with electromagnetic radiation, each stiffener further having a receive antenna at another location of the stiffener for measuring its electromagnetic cavity response.