North Carolina State University

United Technologies Corporation

Sikorsky Aircraft Corporation

Anindya Ghoshal

Zaffir A Chaudhry

Herbert A Chin

Mark W Davis

Mark J Schulz

Mannur J Sundaresan

Leroy H Favrow

David A Haluck

Ronald I Holland

James L Ambler

Lucy M Favrow, Legal Representative

Jeffrey R Schaff

Roxana Zangor

A method for testing ball bearings includes applying a Hertzian contact stress on a ball bearing to provide a fracture of the ball bearing that releases acoustic energy, establishing a signal representing the acoustic energy, and identifying occurrence of the fracture based upon the signal.

Acoustic method and apparatus for fracture detection of ball bearings

A sensor array for non-destructively monitoring a structure to detect a critical structural event. The sensor array includes a plurality of discrete sensor nodes, each of the discrete sensor nodes producing an electrical signal in response to a structural event. A signal adder is electrically connected to the plurality of discrete sensor nodes for receiving and combining the electrical signal from each of the discrete sensor nodes to form a single sensor array output signal. A signal processing module then receives and processes the single sensor output signal. In the preferred embodiment, the signal processing module uses the time interval between the electrical signals from each of the discrete sensor nodes formed into a single sensor array output signal to calculate the location of the critical structural event. Also, in the preferred embodiment, a data collection system is located downstream of the sensor processing module.

System for damage location using a single channel continuous acoustic emission sensor

A sensor array for nondestructively monitoring a structure to detect a critical event. The sensor array includes a plurality of discrete sensor nodes, each of the discrete sensor nodes producing an electrical signal in response to a structural event. In the preferred embodiment, the sensor nodes include a plurality of piezoceramic fibers arranged in a planar array in which the fibers are aligned substantially parallel to each other, each of the fibers having a plurality of polarized regions that are substantially oriented according to their polarity in either a series, parallel, or combined arrangement of series and parallel orientations, and an electrical interface connecting the plurality of polarized regions of each fiber in series with one another. A signal adder receives and combines the electrical signals from each of the discrete sensor nodes to form a single sensor array output signal. In the preferred embodiment, the electrical interface further includes at least one electrical bus substantially aligned with the fibers and a signal processing module for receiving and processing the single sensor output signal. The signal processing module is linked through the digital data bus to a central processing unit. The plurality of discrete sensor nodes may further be divided into discrete subgroups, each located at a different structural location to provide a degree of sensing and determining the location of the structural event. In the preferred embodiment, the discrete sensor nodes are electrically connected in series, thereby forming a continuous series connection between each of the discrete sensor nodes to improve the likelihood that a critical structural event will be detected.

Sensor array system

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Middletown, CT, United States of America

Anindya Ghoshal