Structure with intrinsic damage control, manufacturing processes and method of use

• US 5,309,533 A
• Filed: 12/11/1992
• Issued: 05/03/1994
• Est. Priority Date: 12/11/1991
• Status: Expired due to Term

• Current Assignee: Thomson-CSF
• Original Assignee: Thomson-CSF
• Inventors: Perrier, Bernard, Chazelas, Jean, Estang, Bernard, Bonniau, Philippe, Lecuellet, Jerome
• Primary Examiner(s): FONT, FRANK G
• Application Number:
  US07/989,568
• Time in Patent Office: 508 Days
• Field of Search: 385/11, 385/12, 385/13, 385/100, 385/109, 385/111, 385/123, 385/126, 385/127, 385/128, 250/227.14, 250/227.16, 250/227.17
• US Class Current: 385/11
• CPC Class Codes: G01B 11/16 for measuring the deformation in a solid, e.g. optical strain gauge
• CPC Class Codes: G01D 5/344 using polarisation G01D5/35303 takes precedence
• CPC Class Codes: G01L 1/242 the material being an optical fibre

Abstract

A structure which includes a composite material formed of a plurality sheets forming plies. A casing is formed between two of the plurality of sheets forming the composite material, the casing having an internal diameter. Further, an optical fiber is located within the casing and has an external diameter which is less than the internal diameter of the casing, the optical fiber also having a slow axis and a fast axis of propagation.

Claims

1. A structure comprising:

a composite material comprising a plurality of sheets forming plies;

a casing formed between two of the plurality of sheets forming the composite material, the casing having an internal diameter;

an optical fiber located within the casing and having an external diameter which is less than the internal diameter of the casing, the optical fiber having a slow axis and a fast axis of propagation, wherein the optical fiber comprises;

an optical core;

a sheath surrounding the optical core and comprising at least two longitudinal channels positioned symmetrically with respect to the optical core.

2. A structure according to claim 1, wherein the optical fiber further comprises an overlayer surrounding the sheath.

3. A structure according to claim 2, wherein the casing and the overlayer are formed of materials having a good sliding coefficient with respect to each other.

4. A structure according to claim 3, wherein the casing and the overlayer are formed of teflon.

5. A structure according to claim 1, wherein the casing is formed between two central sheets forming plies of the composite material.

6. A structure according to claim 1, wherein the composite material further comprises a central core, and wherein the casing is formed between the central core and the plurality of sheets forming plies.

7. A structure comprising:

a composite material comprising a plurality of sheets forming plies;

a casing formed between two of the plurality of sheets forming the composite material, the casing having an internal diameter;

an optical fiber located within the casing and having an external diameter which is less than the internal diameter of the casing to thereby form a gap between the optical fiber and casing, the optical fiber having a slow axis and a fast axis of propagation.

8. A structure according to claim 7, wherein the optical fiber comprises an optical core and a sheath surrounding the optical, the sheath comprising at least two longitudinal channels positioned symmetrically with respect to the optical core.

9. A structure according to claim 8, wherein the optical fiber further comprises an overlayer surrounding the sheath.

10. A structure according to claim 9, wherein the casing and the overlayer are formed of materials having a good sliding coefficient with respect to each other.

11. A structure according to claim 10, wherein the casing and the overlayer are formed of teflon.

12. A structure according to claim 7, wherein the casing is formed between two central sheets forming plies of the composite material.

13. A structure according to claim 7, wherein the composite material further comprises a central core, and wherein the casing is formed between the central core and the plurality of sheets forming plies.