MAPPING TOW SPLICES IN COMPOSITE STRUCTURES

• US 20110017380A1
• Filed: 07/26/2009
• Published: 01/27/2011
• Est. Priority Date: 07/26/2009
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Hannebaum, Reed, Rector, Eric, Engelbart, Roger W.
• Granted Patent: US 8,753,458 B2
• Time in Patent Office: Days
• US Class Current: 156/64
• CPC Class Codes: B29C 70/384 Fiber placement heads, e.g. component parts, details or accessories

Abstract

The three dimensional (3-D) locations of splices in pre-preg tows placed by an automatic fiber placement machine to form a laminated composite structure are mapped to allow visualization of alignment patterns in the splices.

Claims

1. A method of mapping the location of splices in tows used to layup a laminated composite structure, comprising:

sensing the location of each splice as tows are being placed during the layup;

generating a data file representing the three dimensional (3-D) location the splices in the structure; and

,

using the data file to generate a 3-D display showing the 3-D location of the splices in the structure.

2. The method of claim 1, wherein sensing the location of each splice includes optically sensing the presence of a feature on the tows representing the location of a splice.

3. The method of claim 2, wherein:

sensing the location of each splice further includes illuminating the tows as the tows are being placed, and

optically sensing the presence of the feature is performed using a camera.

4. The method of claim 3, wherein:

the feature includes visual indicia at each of the splices, and

optically sensing the presence of the feature includes using the camera to record an image of the indicia.

5. The method of claim 1, wherein generating the 3-D display including generating a 3-D display of the structure having the 3-D locations of the splices shown therein.

6. The method of claim 1, wherein generating the data file includes recording the location of each of the sensed splices in each of a plurality of plies of the structure.

7. A method of laying up a composite structure, comprising:

placing tows on a tool using an automatic placement machine;

sensing splices in each of the tows as the tows are placed on the tool;

recording the location of each splice as the splice is sensed; and

,

generating an image of the structure showing the locations of the splices in the structure based on the recorded locations of the splices.

8. The method of claim 7, wherein:

placing the tows includes simultaneously placing a plurality of the tows on the tool as a band, and

sensing the splices includes sensing splices in each of the tows of the band is being placed on the tool.

9. The method of claim 8, wherein:

illuminating the band as the band is being placed on the tool, and

sensing the passage of indicia through a strip across the band.

10. The method of claim 7, wherein recording the location includes recording the two dimensional position of each of the splices in each of a plurality of plies laid up on the tool by the machine.

11. The method of claim 10, further comprising:

using the recorded positions of the splices to generate a data file representing a 3-D image of the locations of the splices in the structure

12. The method of claim 7, wherein sensing splices is performed using sensors mounted on the automatic placement machine.

13. Apparatus for mapping the locations of splices in tows placed by an automatic fiber placement machine, comprising:

means for detecting the splices as each of the tows is being placed by the machine;

means for recording the location of each of the detected splices; and

means for generating a three dimensional (3-D) display of the structure showing the location of the splices.

14. The apparatus of claim 13, wherein the detecting means includes:

means for illuminating the tows as the tows are being placed, and

sensing means for sensing the presence of each of the splices illuminated by the illuminating means.

15. The apparatus of claim 14, wherein the sensing means includes a camera adapted to be mounted on the placement machine and oriented to image an area of the tows immediately after they are placed on the tool.

16. The apparatus of claim 13, wherein the means for recording the location of each of the detected splices includes a computer.

17. The apparatus of claim 16, further comprising a software program used by the computer to generate a 3-D data file representing a 3-D image of the structure showing the location of the splices in the structure.

18. Apparatus for mapping the three dimensional (3-D) location of splices in pre-preg tows placed by an automatic fiber placement machine to form a laminated composite structure, comprising:

at least one sensor for sensing a splice as a tow is being placed;

a computer coupled with the sensor for calculating the 3-D position within the structure of each of the splices sensed by the sensor; and

a display coupled with the computer for displaying an image showing the 3-D position of the splices in the structure.

19. The apparatus of claim 18, wherein the sensor includes an image recording device.

20. The apparatus of claim 19, further comprising means for illuminating the tows are the tows are being placed.

21. The apparatus of claim 20, wherein the illuminating means includes a laser.

22. The apparatus of claim 19, wherein the image recording device and the illuminating means are mounted on the fiber placement machine.

23. The apparatus of claim 18, wherein the tows include features at each of the splices, and the sensor senses the presence of the features.

24. A method of laying up a composite aircraft structure, comprising:

placing bands of composite pre-preg tows on a tool using an automatic placement machine;

sensing features on each of the tows in the band indicating the presence of a splice on the tow immediately after the tow has been placed on the tool by the placement machine;

recording the location of each detected feature within each ply of the lay-up;

retrieving geometric information defining the geometry of the structure;

using the recorded locations of the detected splices and the retrieved geometric information to generate a data file representing the 3-D location of splices within the structure; and

using the 3-D file to generate a 3-D image of the structure showing the location of the splices within the structure.

25. Apparatus for manufacturing a laminated composite aircraft structure, comprising:

an automatic fiber placement machine, including a tape application head for placing bands of pre-preg tows on a tool surface;

at least one camera on the application head for imaging areas of the band immediately after the tows have been placed on the tool surface by the placement head and for recoding the locations of features on the tows representing the presence of a splice in the tow;

a laser for illuminating the area of the band imaged by the camera;

a programmed computer coupled with the camera for recognizing the features recorded by the camera and for generating a 3-D data file representing a 3-D image of the structure that includes the locations of the splices; and

a display coupled with the programmed computer for displaying the 3-D image of the structure including the 3-D locations of the splices.