In-situ on-line structural failure detection system, its preparation and operation
First Claim
1. An in-situ on-line structural failure detection system for use in detecting cracks in metal structures which comprises a thin film adhesively bonded to the metal structural surface to be monitored, said film containing a plurality of thin continuous metal strips which are adapted to be broken when a crack appears under the strips, said strips being substantially parallel but insulated from each other and the metal structural surface and arranged in a pattern such that there is frequent change in direction of the strips as in a zig-zag or rectangular pattern, each of said strips constituting a separate circuit joined to an electric power source and a sensing and recording means capable of detecting and recording any circuit failure which may be caused by disruption of the metal strips.
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Accused Products
Abstract
Structural failures, as in metal aircraft structures, are rapidly detected and measured by use of a new detection system comprising a thin film adhesively bonded to the metal structural surface to be monitored, said film containing a plurality of thin continuous strips which are adapted to be broken when a crack appears under the strips, said strips being substantially parallel but insulated from each other and the metal structural surface and arranged in a pattern such that there is frequent change in direction of the strips as in a zig-zag or rectangular pattern, each of said strips constituting a separate circuit joined to an electric power source and a sensing and recording means capable of detecting and recording any circuit failure caused by disruption of the metal strip, said disruption being caused by the formation of a crack under the said strip.
58 Citations
19 Claims
- 1. An in-situ on-line structural failure detection system for use in detecting cracks in metal structures which comprises a thin film adhesively bonded to the metal structural surface to be monitored, said film containing a plurality of thin continuous metal strips which are adapted to be broken when a crack appears under the strips, said strips being substantially parallel but insulated from each other and the metal structural surface and arranged in a pattern such that there is frequent change in direction of the strips as in a zig-zag or rectangular pattern, each of said strips constituting a separate circuit joined to an electric power source and a sensing and recording means capable of detecting and recording any circuit failure which may be caused by disruption of the metal strips.
- 15. A process for detecting structural failures in metal surfaces as evidenced by the appearance of a crack in the metal surface which process comprises applying to the metal surface to be monitored a thin adhesively bonded film, said film containing a plurality of thin continuous metallic strips which are adapted to be broken when a crack appears under the said strips, said strips being substantially parallel but insulated from each other and the metal structural surface and arranged in a pattern such that there is a frequent change in direction of the strips as in a zig-zag or rectangular pattern, each of said strips constituting a separate circuit joined to an electric power source and a sensing and recording means capable of detecting and recording any circuit failure such as may be caused by disruption of the metal strips, passing a current through each of the said metal strip circuits and monitoring the sensing and recording means so as to detect the formation of any cracks on the metal surface.
Specification