US5539656A — Crack monitoring apparatus

Claim 1

Independent Claim 165 words

An apparatus for monitoring cracks in a specimen, comprising: a. means for applying a load to a specimen, wherein said means for applying a load has a frequency; b. means for illuminating the specimen during the application of a load, wherein said illuminating means has a frequency greater than or equal to said frequency of said means for applying a load; c. means for capturing images of the specimen, wherein said capturing means is synchronized with said illuminating means such that crack formation images can be obtained during the application of a load; d. means for processing images obtained by said image capturing means to produce crack data real-time; and e. a means for controlling having a means for receiving data from said processing means or data input by an operator wherein said means for controlling controls said means for applying a load, said illuminating means, or said image capturing means by using data from said processing means or said data input by an operator.

Claim 2

Independent Claim 165 words

An apparatus for monitoring cracks in a specimen, comprising: a. means for applying a load to a specimen, wherein said means for applying a load has a frequency; b. means for illuminating the specimen during the application of a load, wherein said illuminating means has a frequency greater than or equal to said frequency of said means for applying a load; c. means for capturing images of the specimen, wherein said capturing means is synchronized with said illuminating means such that crack formation images can be obtained during the application of a load; d. means for processing images obtained by said image capturing means to produce crack data real-time; and e. a means for controlling having a means for receiving data from said processing means or data input by an operator wherein said means for controlling controls said means for applying a load, said illuminating means, or said image capturing means by using data from said processing means or said data input by an operator.

Claim 3

Dependent Claim 40 words

The apparatus of claim 1, wherein said means for applying a load is for applying a loading regime to the specimen which simulates of the loading regime of an actual structural component composed of the same material as the specimen.

Claim 4

Dependent Claim 25 words

The apparatus of claim 1, wherein the means for illuminating the specimen and the specimen are arranged to provide as much image contrast as possible.

Claim 5

Dependent Claim 21 words

The apparatus of claim 1, wherein said frequency of said illuminating means and said means for applying a load are synchronized.

Claim 6

Dependent Claim 48 words

The apparatus of claim 1, wherein the means for processing includes means for digitizing a first captured image, storing said first captured-digitized image, digitizing a second captured image, then subtracting out the first captured-digitized image from said second captured-digitized image, integrating the subtracted images, and estimating crack growth.

Claim 7

Dependent Claim 17 words

The apparatus of claim 1, further comprising a means for storing and printing the crack growth data.

Claim 8

Dependent Claim 15 words

The apparatus of claim 1 wherein said means for illuminating comprises fiber optic light guides.

Claim 9

Dependent Claim 14 words

The apparatus of claim 1, wherein said image capturing means includes a magnification means.

Claim 10

Dependent Claim 20 words

The apparatus of claim 8, wherein said magnification means is a microscope, a macrophoto lens, or an electronic magnification means.

Claim 11

Independent Claim 155 words

A method for monitoring cracks in a specimen, comprising the steps of; a. applying a load to the specimen with a means for applying a load, wherein said means for applying a load has a frequency; b. illuminating the specimen during the application of the load to accentuate the formation of cracks with an illuminating means having a frequency greater than or equal to the frequency of the means for applying a load; c. capturing images of the specimen during the loading regime, wherein said illuminating and capturing are synchronized with one another; d. processing the captured images to obtain crack data real-time; and e. controlling, with a means for controlling having a means for receiving data from said processing means or data input by an operator, said means for applying a load, said illuminating means, or said image capturing means by using data from said processing means or said data input by an operator.

Claim 12

Independent Claim 155 words

A method for monitoring cracks in a specimen, comprising the steps of; a. applying a load to the specimen with a means for applying a load, wherein said means for applying a load has a frequency; b. illuminating the specimen during the application of the load to accentuate the formation of cracks with an illuminating means having a frequency greater than or equal to the frequency of the means for applying a load; c. capturing images of the specimen during the loading regime, wherein said illuminating and capturing are synchronized with one another; d. processing the captured images to obtain crack data real-time; and e. controlling, with a means for controlling having a means for receiving data from said processing means or data input by an operator, said means for applying a load, said illuminating means, or said image capturing means by using data from said processing means or said data input by an operator.

Claim 13

Dependent Claim 32 words

The method of claim 10, wherein the loading regime is applied to the specimen to simulate the loading regime of an actual structural component composed of the same material as the specimen.

Claim 14

Dependent Claim 20 words

The method of claim 10, wherein the specimen is oriented to provide as much image contrast as possible during illumination.

Claim 15

Dependent Claim 18 words

The method of claim 10, wherein said illumination and said application of a load occur at synchronized frequencies.

Claim 16

Dependent Claim 21 words

The method of claim 10, wherein said illumination and said image capturing occurs at a like point in the loading regime.

Claim 17

Dependent Claim 29 words

The method of claim 10, wherein said illumination and said image capturing occur at a point in the loading regime where a crack is opened to its maximum dimension.

Claim 18

Dependent Claim 38 words

The method of claim 10, wherein said processing includes digitizing a first captured image, storing said first captured-digitized image, subtracting out the first captured image from a second captured-digitized image, integrating the subtracted images, and estimating crack growth.

Claim 19

Dependent Claim 14 words

The method of claim 10, further comprising storing and printing the crack growth data.

Claim 20

Dependent Claim 15 words

The method of claim 10, wherein the specimen is illuminated with fiber optic light guides.

Claim 21

Dependent Claim 10 words

The method of claim 10, further comprising magnifying the image.

Claim 22

Dependent Claim 25 words

The method of claim 10, further comprising preparing the specimen such that grain boundaries and other microstructural features will not inhibit the monitoring of cracks.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1999-07-23	2000-01-22	2000-07-23	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2003-07-23	2004-01-22	2004-07-23	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2007-07-23	2008-01-22	2008-07-23	$7700.00	Window Closed / Lapsed

Crack monitoring apparatus

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