Donald F Lyons

US Patent:

55535046, Sep 10, 1996

Filed:

Oct 19, 1995

Appl. No.:

8/545167

Inventors:

Donald R. Lyons - Melville NY
Stanley M. Reich - Jericho NY
Peter Shyprykevich - Margate NJ

Assignee:

Grumman Aerospace Corporation - Los Angeles CA

International Classification:

G01N 1908

US Classification:

73799

Abstract:

An apparatus for preventing, detecting, and predicting the formation and propagation of cracks in structural members. The apparatus includes a plurality of strain sensors integrally formed with a patch to be fixed to an area on the surface of a structural member. The patch operates to reduce stress levels in the patch-covered area for deterring the formation or propagation of a crack therein. The sensors monitor changes in the strain field in the patch-covered area for detecting crack formation and detection. The apparatus may also include a temperature-compensating strain sensor and a temperature sensor both integrally formed with the patch for detecting and predicting crack formation and propagation, respectively.

US Patent:

51914581, Mar 2, 1993

Filed:

Jun 12, 1991

Appl. No.:

7/713503

Inventors:

Donald R. Lyons - Melville NY
Stanley M. Reich - Jericho NY

Assignee:

Grumman Aerospace Corporation - Bethpage NY

International Classification:

H04B 1012
H04J 1402

US Classification:

359127

Abstract:

An optical electronic multiplexing reflection sensor system for a plurality of Bragg sensors connected in series spaced relation in a plurality of single mode fiber optic cable buses. In each of the buses a unique address is provided each sensor function by wavelength selection. Each of a plurality of monochromators is coupled to a corresponding one of the buses and has a control connected to it for controlling the operation of the monochromator. A tunable laser source is coupled to each of the buses. A wavelength sweep generator is coupled to the laser source and provides outputs to the controls of the monochromators. Each of a plurality of photodetector receivers receives the output of a corresponding one of the monochromators and each has an output providing output signals indicating individual wavelengths of the Bragg sensors coupled to it. Each if a plurality of analog to digital converters is connected to the output of a corresponding one of the photodetector receivers. A backbone network connected to the analog to digital converters distributes and processes digitized data.