Apparatus for automated crack growth rate measurement
AssigneeThe Firestone Tire & Rubber Company
InventorThomas S. Fleischman
Life of this patent
Estimating the term…
Abstract
Apparatus for monitoring and measuring the growth of a crack in an elastic specimen. The specimen is repeatedly flexed by a piston at a set frequency and periodically slowed to a substantially lower frequency during which time a line scan camera monitors the length of the crack. The camera is positioned such that the specimen is drawn through the scan line thereof. The camera is calibrated such that the output signal from the camera correlates directly to the cracklength. This output signal is digitized, received, and stored by a digital processor for use in determining the crack growth rate.
Claims17
Apparatus for monitoring the growth of a crack in a first edge of an elastic specimen, comprising:
- first means for receiving and flexing the specimen;
- second means in juxtaposition to said first means for optically viewing the specimen in an area including the crack and generating an output signal, said second means comprising a line scan camera and said output signal being a function of the contrast between light and dark in a scan line of said camera, said scan line extending beyond at least the first edge of the specimen;
- and
- third means connected to said second means for collecting and storing data obtained from said output signal.
Apparatus for monitoring the growth of a crack propagating from the edge of an elastic specimen, comprising:
- reciprocating means for receiving and flexing the specimen;
- a line scan camera maintained opposite said reciprocating means and having a scan line extending beyond the edge of the specimen from which the crack propagates;
- and
- processing means connected to said reciprocating means and said camera for controlling the frequency at which the specimen is flexed and periodically receiving data from said camera.
Dependencies are inferred from the claim text.