General Electric Company

Daniel Weinstein

Thomas Pompilio Diaz

Harvey Donald Solomon

Gary W Contreras

Peter Louis Andresen

Gerald M Gordon

William R Catlin

William D Miller

Ronald E De Lair

Ronald Edward DeLair

Veronica L McCarthy

A double cantilever beam (DCB) assembly is disclosed, comprising a fracture specimen having a notch which defines first and second spaced, substantially parallel, outwardly extending beams, terminating at a closed end where crack growth occurs and extending to an open end. The beams are connected to each other along at least a portion of a facing surface of each beam by two, substantially parallel ligaments, spaced from each other on the facing surfaces of the beams. Another disclosed embodiment is a corrosive environment measuring apparatus, comprising a double cantilever beam assembly disposed in an aqueous portion of a reactor vessel, and including the features described above. The reactor vessel is often a constituent of a nuclear reactor, and the DCB assembly is often disposed in a tube which is selectively lowered into the aqueous portion of the reactor vessel. The tube is usually a local power range monitor tube.

Double cantilever beam crack growth sensor

An apparatus and a method for measuring and controlling the crack growth rate within a double cantilever beam type test specimen. The arms of the test specimen are fitted with a pressure-actuated bellows to induce a predetermined load and with a sensing assembly to provide feedback on the amount of beam displacement resulting from application of that load. In this manner a loaded test specimen may be remotely mounted and adjusted inside the reactor pressure vessel or piping of a nuclear reactor in order to maintain a stress intensity which is constant or which varies in a predetermined manner for inducing stress corrosion cracking or corrosion fatigue in the specimen.

Method and apparatus for controlling the load on double cantilever beam

Electrically controlled load activating mechanisms that can be used inside the containment vessel of a nuclear reactor in conjunction with bellows-loaded DCB crack growth sensors installed inside the reactor pressure vessel or piping of a nuclear reactor. One mechanism is a liquid-filled, double-bellows master/slave arrangement connected by a capillary tube to transmit the loading provided by a linear motion device. Another mechanism uses a heat-resistant gas bottle that can be heated in a furnace to increase the gas pressure to expand the bellows of the DCB sensor. A third mechanism uses a pump or compressor to provide the necessary expansion force. The loading is controlled via electrical connections that do not require special pressure boundary penetrations of the containment vessel.

Remote load activating mechanisms

Growing community of inventors

San Jose, CA, United States of America

Daniel Weinstein