Nondestructive inspection method and system
A method and system for nondestructively detecting and quantifying material anomalies within materials, including composite articles. The method entails performing a three-dimensional imaging scan technique, such as a computed tomography scan, of the material and a reference standard such that a test image of the material and a reference image of the reference standard appear in a plurality of two-dimensional scan views generated by the scan technique. The reference images are located in the scan views and normalized to determine at least an average value of the pixel data for the reference images. Values of pixel data of the test image are determined in each scan view, and then compared to the pixel data of the reference images to detect the presence of an anomaly in the test images. The detected anomaly in at least one of the test images of the scan views is then compared to a requirement standard for the material.
1. A nondestructive method of inspecting a material, the method comprising the steps of:
providing a reference standard having a known density;
performing a three-dimensional imaging scan technique on the material and the reference standard such that a test image of the material and a reference image of the reference standard appear together in each of a plurality of parallel two-dimensional scan views generated by the three-dimensional imaging scan technique, the reference images and the test images comprising pixel data corresponding to amounts of scan energies absorbed at each of a plurality of parallel two-dimensional cross-sections of the reference standard and the material;
locating the reference images of the reference standard in the scan views;
normalizing the reference images of the reference standard in the scan views to determine at least an average value of the pixel data for the reference images;
determining values of the pixel data of the test image in each of the scan views;
comparing the values of the pixel data of the test image in each of the scan views to at least the average value of the pixel data of the reference images to detect the presence of an anomaly in the test image in each of the scan views; and
comparing the detected anomaly in at least one of the test images of the scan views to a requirement standard for the material.
2. The nondestructive method according to claim 1 , further comprising the step of removing background noise from the test images of the material prior to comparing the values of the pixel data of the test image in each of the scan views to at least the average value of the pixel data of the reference images.
3. The nondestructive method according to claim 1 , further comprising the step of filtering the test images to mask areas of the scan views outside the cross-sections of the material prior to comparing the values of the pixel data of the test image in each of the scan views to at least the average value of the pixel data of the reference images.
4. The nondestructive method according to claim 1 , further comprising the steps of:
displaying the test images as digital visual test images; and
visually highlighting areas of the digital visual test images corresponding to the presence of the anomaly within the material that exceeds a predetermined threshold.
5. The nondestructive method according to claim 1 , wherein the step of comparing the detected anomaly comprises performing a bulk assessment by comparing the detected anomaly in a plurality of the test images of the scan views to a bulk requirement standard for the material.
6. The nondestructive method according to claim 1 , wherein the material is a composite article comprising a fibrous reinforcement material in a matrix material.
7. The nondestructive method according to claim 6 , wherein the composite article is a ceramic matrix composite material.
8. The nondestructive method according to claim 7 , wherein the ceramic matrix composite material is produced by a melt infiltration process.
9. The nondestructive method according to claim 7 , wherein the ceramic matrix composite article is a component of a gas turbine engine.
10. A nondestructive method of inspecting a composite article comprising a fibrous reinforcement material in a matrix material, the method comprising the steps of:
providing a reference standard having a known density;
performing a computed tomography scan of the composite article and the reference standard such that a test image of the composite article and a reference image of the reference standard appear together in each of a plurality of parallel scan views generated by the computed tomography scan, the reference images and the test images comprising pixel data corresponding to amounts of X-rays absorbed at each of a plurality of parallel two-dimensional cross-sections of the reference standard and the composite article;
locating the reference images of the reference standard in the scan views;
normalizing the reference images of the reference standard in the scan views to determine at least an average value of the pixel data for the reference images;
removing background noise from the test images of the composite article;
filtering the test images to mask areas of the scan views outside the cross-sections of the composite article;
determining values of the pixel data of the test image in each of the scan views;
comparing the values of the pixel data of the test image in each of the scan views to at least the average value of the pixel data of the reference images to detect the presence of a void in the test image in each of the scan views; and
performing a bulk assessment by comparing the detected void in a plurality of the test images of the scan views to a bulk requirement standard for the composite article.
11. The nondestructive method according to claim 10 , wherein the composite article is a ceramic matrix composite material.
12. The nondestructive method according to claim 11 , wherein the ceramic matrix composite material is produced by a melt infiltration process.
13. The nondestructive method according to claim 11 , wherein at least one of the fibrous reinforcement material and the matrix material of the ceramic matrix composite article comprises silicon carbide.
14. The nondestructive method according to claim 11 , wherein the ceramic matrix composite article is a component of a gas turbine engine.
15. A system for nondestructively inspecting a material, the system comprising;
a reference standard having a known density;
means for performing a three-dimensional imaging scan technique on the material and the reference standard such that a test image of the material and a reference image of the reference standard appear together in each of a plurality of parallel two-dimensional scan views generated by the three-dimensional imaging scan technique, the reference images and the test images comprising pixel data corresponding to amounts of scan energies absorbed at each of a plurality of parallel two-dimensional cross-sections of the reference standard and the material;
means for locating the reference images of the reference standard in the scan views;
means for normalizing the reference images of the reference standard in the scan views to determine at least an average value of the pixel data for the reference images;
means for determining values of the pixel data of the test image in each of the scan views;
means for comparing the values of the pixel data of the test image in each of the scan views to at least the average value of the pixel data of the reference images to detect the presence of an anomaly in the test image in each of the scan views; and
means for comparing the detected anomaly in at least one of the test images of the scan views to a requirement standard for the material.
16. The system according to claim 15 , further comprising means for removing background noise from the test images of the material prior to comparing the values of the pixel data of the test image in each of the scan views to at least the average value of the pixel data of the reference images.
17. The system according to claim 15 , further comprising means for filtering the test images to mask areas of the scan views outside the cross-sections of the material prior to comparing the values of the pixel data of the test image in each of the scan views to at least the average value of the pixel data of the reference images.
18. The system according to claim 15 , further comprising:
means for displaying the test images as digital visual test images; and
means for visually highlighting areas of the digital visual test images corresponding to the presence of the anomaly within the material that exceeds a predetermined threshold.
19. The system according to claim 15 , wherein the means for comparing the detected anomaly comprises means for performing a bulk assessment by comparing the detected anomaly in a plurality of the test images of the scan views to a bulk requirement standard for the material.
20. The system according to claim 15 , wherein the material is a ceramic matrix composite material.
21. The nondestructive method according to claim 1 , wherein the material is a monolith article selected from the group consisting of castings, moldings, forgings, and extrusions.
22. The nondestructive method according to claim 6 , wherein the composite article is a polymer matrix composite material.
23. The nondestructive method according to claim 10 , wherein the composite article is a polymer matrix composite material.
24. The system according to claim 15 , wherein the material is a monolith article selected from the group consisting of castings, moldings, forgings, and extrusions.
25. The system according to claim 15 , wherein the material is a polymer matrix composite material.