Systems and methods for detecting crack growth
AssigneeThe Boeing Company
InventorJordan Jerome Handler
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Abstract
A system and method for detecting crack propagation in a material test specimen may include color contrasting a surface of a test specimen, acquiring a plurality of photographic images of the specimen during application of a stress load, processing the plurality of images to detect characteristics of pixels that are outside a baseline range of pixel characteristics indicative of a contrast between a crack in the test specimen and the color contrasted surface of the test specimen, and generating an output of a strain energy release rate based on changes in detected crack length over time.
Claims20
A method of detecting crack propagation in a material test specimen, comprising:
- color contrasting a surface of a test specimen with the surface color of a background;
- supporting the test specimen over the background;
- acquiring a plurality of photographic images of the specimen during application of a stress load;
- processing the plurality of images to detect characteristics of pixels that are outside a baseline range of pixel characteristics indicative of a contrast between the background revealed through a crack in the test specimen and the color contrasted surface of the test specimen;
- and
- generating an output of a strain energy release rate based on changes in detected crack length over time.
A system for detecting crack propagation in a material test specimen, comprising:
- a test platform configured to support a material test specimen on a background, the background having a surface color selected to provide a color contrast with a top surface color of the test specimen;
- a camera directed toward the test platform and configured to acquire a plurality of photographic images of the test specimen located on the platform during application of a stress load to the test specimen;
- and
- an image processing program that receives the plurality of photographic images, and that is configured to:
- detect, in the plurality of photographic images, pixel characteristics of the background revealed through a crack in the test specimen, and
- measure changes in a detected crack length based on the detected pixel characteristics.
A method of detecting crack propagation in a material test specimen, comprising:
- selecting a surface color of a background in a test platform;
- supporting a material test specimen over the background, the specimen having a top surface color contrasting the surface color of the background;
- applying a stress load to the specimen;
- acquiring multiple photographic images of an extending crack length in the specimen during the applying step;
- and
- detecting pixel characteristics of the background revealed through a crack in the specimen that are different from pixel characteristics associated with the top surface color of the specimen to measure crack length in the specimen.
Dependencies are inferred from the claim text.