Wrinkle Characterization and Performance Prediction for Composite Structures

• US 20180120268A1
• Filed: 10/31/2016
• Published: 05/03/2018
• Est. Priority Date: 10/31/2016
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Georgeson, Gary E., Bingham, Jill P., Tat, Hong Hue, Wu, Yuan-Jye, Pryor, John M., Fieni, Sadie L., Winters, Mark D., Moore, Kathryn T., Kennedy, James C., Little, Clayton M., Lin, John Z.
• Granted Patent: US 11,255,825 B2
• Time in Patent Office: Days
• 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 2291/011 Velocity or travel time
• CPC Class Codes: G01N 2291/015 Attenuation, scattering
• 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 2291/044 Internal reflections (echoes), e.g. on walls or defects
• CPC Class Codes: G01N 2291/051 Perpendicular incidence, perpendicular propagation
• CPC Class Codes: G01N 2291/106 one or more transducer arrays
• CPC Class Codes: G01N 2291/2632 flat
• CPC Class Codes: G01N 2291/2694 Wings or other aircraft parts
• CPC Class Codes: G01N 29/043 in the interior, e.g. by shear waves
• CPC Class Codes: G01N 29/0645 Display representation or displayed parameters, e.g. A-, B- or C-Scan
• CPC Class Codes: G01N 29/07 by measuring propagation velocity or propagation time of acoustic waves
• CPC Class Codes: G01N 29/11 by measuring attenuation of acoustic waves
• CPC Class Codes: G01N 29/30 Arrangements for calibrating or comparing, e.g. with standard objects
• CPC Class Codes: G01N 29/4445 Classification of defects
• CPC Class Codes: G06F 30/23 using finite element methods [FEM] or finite difference methods [FDM]

Abstract

Methods that provide wrinkle characterization and performance prediction for wrinkled composite structures using automated structural analysis. In accordance with some embodiments, the method combines the use of B-scan ultrasound data, automated optical measurement of wrinkles and geometry of cross-sections, and finite element analysis of wrinkled composite structure to provide the ability to assess the actual significance of a detected wrinkle relative to the intended performance of the structure. The disclosed method uses an ultrasonic inspection system that has been calibrated by correlating ultrasonic B-scan data acquired from reference standards with measurements of optical cross sections (e.g., micrographs) of those reference standards.

Claims

1. A method for calibrating an ultrasonic inspection system, comprising:

(a) forming a multiplicity of reference standards made of composite material, each reference standard having at least one wrinkle;

(b) collecting ultrasonic B-scan data from the multiplicity of reference standards using an ultrasonic inspection system;

(c) cutting the reference standards to expose cross sections;

(d) imaging the exposed cross sections to produce optical cross sections;

(e) measuring features of the at least one wrinkle of each reference standard which appear in the optical cross sections to acquire optical cross-section measurement data; and

(f) correlating the ultrasonic B-scan data with the optical cross-section measurement data.

2. The method as recited in claim 1, wherein the optical cross-section measurement data comprises data representing wavelengths and maximum depths of wrinkles in respective reference standards of the multiplicity of reference standards.

3. The method as recited in claim 2, wherein the optical cross-section measurement data further comprises data representing thicknesses of the respective reference standards.

4. The method as recited in claim 3, wherein step (f) comprises correlating time-of-flight measurements with material depths.

5. The method as recited in claim 4, further comprising selecting time and depth axes ranges and time-gate settings for a B-scan window based on results of step (f), including the correlating of the time-of-flight measurements with the material depths.

6. An ultrasonic imaging system having a B-scanning mode in which time and depth axes ranges and time-gate settings for a B-scan window are based on a correlation of ultrasonic B-scan data with optical cross-section measurement data.

7. The ultrasonic imaging system as recited in claim 6, wherein the optical cross-section measurement data comprises data representing wavelengths and maximum depths of wrinkles in respective reference standards.

8. The ultrasonic imaging system as recited in claim 7, wherein the optical cross-section measurement data further comprises data representing thicknesses of the respective reference standards.

9. A method for non-destructive inspection of composite structures, comprising:

(a) calibrating an ultrasonic inspection system based on correlation of ultrasonic B-scan data and optical cross-section measurement data acquired from reference standards made of composite material, each reference standard having at least one wrinkle;

(b) collecting non-destructive inspection data from a part made of composite material using the ultrasonic inspection system after completion of step (a);

(c) detecting the presence of a wrinkle in the part based on the non-destructive inspection data collected in step (b);

(d) collecting ultrasonic B-scan data from the part using the ultrasonic inspection system; and

(e) measuring dimensions of the wrinkle in the part based on the ultrasonic B-scan data collected in step (d).

10. The method as recited in claim 9, wherein the non-destructive inspection data is collected in step (b) using at least one of the following:

an ultrasound technique, infrared thermography, or an X-ray backscatter technique.

11. The method as recited in claim 9, further comprising generating a structural model of the part and performing a structural analysis of the structural model.

12. The method as recited in claim 11, further comprising determining whether the part should be rejected or not based on results of the structural analysis.

13. The method as recited in claim 11, wherein the structural model is a finite element model and the structural analysis is a finite element model analysis.

14. A method for non-destructive inspection of composite structures, comprising:

(a) calibrating an ultrasonic inspection system based on correlation of ultrasonic B-scan data and optical cross-section measurement data acquired from reference standards made of composite material, each reference standard having at least one wrinkle;

(b) collecting ultrasonic B-scan data from a part made of composite material using the ultrasonic inspection system after completion of step (a);

(c) detecting the presence of a wrinkle in the part based on the ultrasonic B-scan data collected in step (b); and

(d) measuring dimensions of the wrinkle in the part based on the ultrasonic B-scan data collected in step (b).

15. The method as recited in claim 14, further comprising generating a structural model of the part and performing a structural analysis of the structural model.

16. The method as recited in claim 15, further comprising determining whether the part should be rejected or not based on results of the structural analysis.

17. The method as recited in claim 15, wherein the structural model is a finite element model and the structural analysis is a finite element model analysis.

18. A method for predicting performance of a wrinkled composite structure, comprising:

(a) calibrating an ultrasonic inspection system based on correlation of ultrasonic B-scan data and optical cross-section measurement data acquired from reference standards made of composite material, each reference standard having at least one wrinkle;

(b) collecting ultrasonic B-scan data from a wrinkled composite structure using the ultrasonic inspection system after completion of step (a);

(c) measuring dimensions of a wrinkle in the wrinkled composite structure based on the ultrasonic B-scan data collected in step (b) to obtain wrinkle feature measurements;

(d) generating a structural model of the wrinkled composite structure based on the wrinkle feature measurements obtained in step (c); and

(e) performing a structural analysis of the structural model.

19. The method as recited in claim 18, further comprising determining whether the wrinkled composite structure should be rejected or not based on results of the structural analysis.

20. The method as recited in claim 18, wherein the structural model is a finite element model and the structural analysis is a finite element model analysis.