Composite laminate enabling structural monitoring using electromagnetic radiation

Patent metadata

Field	Value
Publication number	US-10099465-B2
Application number	US-201414312668-A
Country	US
Kind code	B2
Filing date	Jun 23, 2014
Priority date	Jan 5, 2012
Publication date	Oct 16, 2018
Grant date	Oct 16, 2018

Abstract

Electromagnetic radiation scanning is used to monitor the integrity of a composite laminate structure. The composite laminate structure is optically resonant at a frequency of electromagnetic radiation, allowing inconsistencies in the laminate to be detected and mapped.

First claim

What is claimed is:

1. A method for enabling structural monitoring using electromagnetic radiation, the method comprising:
providing a source of electromagnetic radiation; and
providing a composite laminate in an aircraft fuselage comprising:
a first portion comprising a laminated stack of resin layers and unidirectional reinforcement fibers between the resin layers, the first portion having a depth, wherein each of the resin layers has an index of refraction between 1.4 and 2.4, wherein the first portion is anti-reflective to a wavelength of an electromagnetic radiation of a microwave X-band between 5 mm and 50 mm; and
a second portion consisting of an inconsistency that is located within the first portion and that is reflective to the wavelength;
wherein the wavelength of the electromagnetic radiation penetrates the depth of the first portion except where it encounters the second portion and is reflected by the second portion.

2. The method of claim 1 , further comprising:
wherein an approximate thickness of each of the resin layers is based on a preselected electromagnetic radiation frequency; and
wherein the laminated stack of resin layers has a resonance at the preselected electromagnetic radiation frequency.

3. the method of claim 1 , further comprising:
detecting and mapping the inconsistency.

4. The method of claim 1 , wherein the inconsistency is an air bubble.

5. The method of claim 1 , wherein the inconsistency is a void.

6. The method of claim 1 , wherein the inconsistency is a ripple.

7. The method of claim 1 , wherein the inconsistency is a wave in fiber alignment.

8. The method of claim 1 , wherein the inconsistency is a balling or a bunching of fibers.

9. The method of claim 1 , wherein the inconsistency is a cracking.

10. The method of claim 1 , wherein the inconsistency is a delamination.

11. The method of claim 1 , wherein the inconsistency is a change in material.

12. The method of claim 1 , wherein the inconsistency is a change in a structural property.

13. The method of claim 1 , wherein the resin layers in the laminated stack of resin layers are stacked on top of each other.

14. The method of claim 1 , wherein each of the resin layers has an approximate thickness that is based on a preselected electromagnetic radiation frequency.

15. The method of claim 1 , wherein orientations of the unidirectional reinforcement fibers between the resin layers are sequenced in the laminated stack.

16. The method of claim 15 , wherein, wherein the orientations of the unidirectional reinforcement fibers are determined by a frequency of the electromagnetic radiation.

17. The method of claim 1 , wherein the unidirectional reinforcement fibers are between alternating resin layers.

18. The method of claim 1 , wherein the unidirectional reinforcement fibers are oriented generally perpendicular to each other.

19. The method of claim 1 , wherein the unidirectional reinforcement fibers include carbon.

20. The method of claim 1 , wherein the resin layers include epoxy.

21. The method of claim 2 , wherein the inconsistency, wherein the inconsistency in the second portion disrupts the resonance at the preselected electromagnetic radiation frequency.

Assignees

• Boeing Co

Inventors

• Clemen Jr Mark J

Classifications

• B32B2307/212

  Electromagnetic interference shielding · CPC title

• G01N22/02

  Investigating the presence of flaws · CPC title

• Y10T428/24058

  including grain, strips, or filamentary elements in respective layers or components in angular relation · CPC title

• B32B2307/732

  Dimensional properties · CPC title

• Y10T428/24942

  including components having same physical characteristic in differing degree · CPC title