IN-SITU OPTICAL CRACK MEASUREMENT USING A DOT PATTERN
First Claim
1. A method of detecting cracks in an object, the method comprising:
- capturing a first image of a pattern of marks in a region of interest on a surface of the object;
constructing a finite element model of the region of interest having nodes corresponding to the marks in the pattern;
subjecting the object to a first mechanical load to produce strains in the object;
capturing a second image of the pattern;
computing strains in the object based on relative changes in locations of the marks in the first and second images;
modifying the finite element model to produce a crack versus surface strain map;
capturing a third image of the pattern; and
comparing the locations of marks in the third image to the crack versus surface strain map to identify a crack in the object.
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Accused Products
Abstract
A method of detecting cracks in an object includes: capturing a first image of a pattern of marks in a region of interest on a surface of the object; constructing a finite element model of the region of interest having nodes corresponding to the marks in the pattern; subjecting the object to a first mechanical load to produce strains in the object; capturing a second image of the pattern; computing strains in the object based on relative changes in locations of the marks in the first and second images; modifying the finite element model to produce a crack versus surface strain map; capturing a third image of the pattern; and comparing the locations of marks in the third image to the crack versus surface strain map to identify a crack in the object. An apparatus that performs the method is also provided.
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Citations
17 Claims
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1. A method of detecting cracks in an object, the method comprising:
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capturing a first image of a pattern of marks in a region of interest on a surface of the object; constructing a finite element model of the region of interest having nodes corresponding to the marks in the pattern; subjecting the object to a first mechanical load to produce strains in the object; capturing a second image of the pattern; computing strains in the object based on relative changes in locations of the marks in the first and second images; modifying the finite element model to produce a crack versus surface strain map; capturing a third image of the pattern; and comparing the locations of marks in the third image to the crack versus surface strain map to identify a crack in the object. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An apparatus for detecting cracks in an object, the apparatus comprising:
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an image capture device for capturing first, second and third images of a pattern of marks in a region of interest on a surface of the object; and a processor for implementing a finite element model of the region of interest having nodes corresponding to the marks in the pattern, computing strains in the object based on relative changes in locations of the marks in the first and second images after the object has been subject to a mechanical load, modifying the finite element model to produce a crack versus surface strain map, and comparing the locations of marks in the third image to the crack versus surface strain map to identify a crack in the object. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17)
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Specification