Methods and systems for inspection of composite irregularities

• US 9,595,092 B2
• Filed: 05/10/2013
• Issued: 03/14/2017
• Est. Priority Date: 05/10/2013
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Koltenbah, Benjamin E. C., Wu, Yuan-Jye, Tat, Hong, Wu, Vicki
• Primary Examiner(s): TSAI, TSUNG YIN
• Application Number:
  US13/891,688
• Publication Number:
  US 20140333758A1
• Time in Patent Office: 1,404 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G01N 2021/8438 Mutilayers
• CPC Class Codes: G01N 2021/8472 Investigation of composite materials
• CPC Class Codes: G01N 21/88 Investigating the presence of flaws or contamination
• CPC Class Codes: G01N 21/8851 Scan or image signal processing specially adapted therefor, e.g. for scan signal adjustment, for detecting different kinds of defects, for compensating for structures, markings, edges G01N21/8806 and G01N21/93 - G01N21/95692 take precedence; optical measurement of dimensions G01B11/00; optical scanning G02B26/10; image transformation G06T3/00; computerised image enhancement G06T5/00; image processing per se for flaw detection G06T7/0002
• CPC Class Codes: G01N 21/95 characterised by the material or shape of the object to be examined G01N21/89 - G01N21/91, G01N21/94 take precedence
• CPC Class Codes: G01N 2291/0231 Composite or layered materials
• CPC Class Codes: G01N 2291/0289 Internal structure, e.g. defects, grain size, texture
• CPC Class Codes: G01N 29/069 Defect imaging, localisation and sizing using, e.g. time of flight diffraction [TOFD], synthetic aperture focusing technique [SAFT], Amplituden-Laufzeit-Ortskurven [ALOK] technique
• CPC Class Codes: G01N 29/4454 Signal recognition, e.g. specific values or portions, signal events, signatures
• CPC Class Codes: G06T 2207/10132 Ultrasound image
• CPC Class Codes: G06T 2207/30164 Workpiece; Machine component
• CPC Class Codes: G06T 7/0004 Industrial image inspection

Abstract

A method for inspecting a composite structure includes acquiring an image of the composite structure. The composite structure includes at least a first ply and a second ply adjacent the first ply. The method also includes transforming the image into a binary image, and determining a first boundary line between the first ply and the second ply. The method further includes characterizing an irregularity in the composite structure based at least partially on the first boundary line.

Claims

1. A method of inspecting a composite structure, said method comprising:

acquiring an ultrasound B-scan cross-sectional image of a depth of the composite structure, wherein the depth of the composite structure is defined by at least a first ply and a second ply laid up on the first ply, the cross-sectional ultrasound B-scan image representing intensity information of a plurality of A-scan ultrasound waves plotted in grayscale;

transforming the acquired ultrasound B-scan cross-sectional image into a binary image;

determining a first boundary line between the first ply and the second ply based at least partially on a position of each of a plurality of data points plotted in the binary image;

calculating a vertical height as a difference between a minimum vertical location and a maximum vertical location of the first boundary line determined in the binary image;

characterizing, based on the binary image, presence of a wrinkle and associated wrinkle height relative to the depth of the composite structure acquired from the binary image of the ultrasound B-scan cross-sectional image, wherein the wrinkle is characterized when the calculated vertical height of the first boundary line determined in the binary image is greater than a predetermined threshold; and

displaying a virtual representation of the characterized wrinkle on the acquired binary image of the ultrasound B-scan cross-sectional image.

2. A method in accordance with claim 1, wherein acquiring the cross-sectional image comprises acquiring a photomicrograph of the cross-section of the composite structure.

3. A method in accordance with claim 1 further comprising determining a shape of the first boundary line, and determining a second boundary line based at least partially on the shape of the first boundary line.

4. A computer-readable storage device having encoded thereon computer readable instructions that are executable by a processor to perform functions comprising:

acquiring an ultrasound B-scan cross-sectional image of a depth of a composite structure, wherein the depth of the composite structure is defined by at least a first ply and a second ply laid up on the first ply, the cross-sectional ultrasound B-scan image representing intensity information of a plurality of A-scan ultrasound waves plotted in grayscale;

transforming the acquired ultrasound B-scan cross-sectional image into a binary image;

determining a first boundary line between the first ply and the second ply based at least partially on a position of each of a plurality of data points plotted in the binary image;

calculating a vertical height as a difference between a minimum vertical location and a maximum vertical location of the first boundary line determined in the binary image;

characterizing, based on the binary imam presence of a wrinkle and associated wrinkle height relative to the depth of the composite structure acquired from the binary image of the ultrasound B-scan cross-sectional image, wherein the wrinkle is characterized when the calculated vertical height of the first boundary line determined in the binary image is greater than a predetermined threshold; and

displaying a virtual representation of the characterized wrinkle on the acquired binary image of the ultrasound B-scan cross-sectional image.

5. A computer-readable storage device in accordance with claim 4, wherein the instructions are executable by the processor to perform functions comprising acquiring a photomicrograph of the cross-section of the composite structure.

6. A computer-readable storage device in accordance with claim 4, wherein the instructions are executable by the processor to perform functions comprising determining a shape of the first boundary line, and determining a second boundary line based at least partially on the shape of the first boundary line.

7. A system comprising:

a scanning module configured to acquire an ultrasound B-scan cross-sectional image of a depth of a composite structure, wherein the depth of the composite structure is defined by at least a first ply and a second ply laid up on the first ply, the cross-sectional ultrasound B-scan image representing intensity information of a plurality of A-scan ultrasound waves plotted in grayscale;

a binary imaging module configured to transform the acquired ultrasound B-scan cross-sectional image into a binary image; and

an evaluating module configured to determine a first boundary line between the first ply and the second ply based at least partially on a position of each of a plurality of data points plotted in the binary image, calculate a vertical height as a difference between a minimum vertical location and a maximum vertical location of the first boundary line determined in the binary image, characterize, based on the binary image, presence of a wrinkle and associated wrinkle height relative to the depth of the composite structure acquired from the binary image of the ultrasound B-scan cross-sectional image, wherein the wrinkle is characterized when the calculated vertical height of the first boundary line determined in the binary image is greater than a predetermined threshold, and display a virtual representation of the characterized wrinkle on the acquired binary image of the ultrasound B-scan cross-sectional image.

8. A system in accordance with claim 7, wherein the scanning module is configured to acquire a photomicrograph of the cross-section of the composite structure.

9. A system in accordance with claim 7, wherein the evaluating module is configured to determine a shape of the first boundary line, and determine a second boundary line based at least partially on the shape of the first boundary line.