Nondestructive inspection method and system

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.

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.