CANDU 3 rolled joint development program. outlet end fitting to pressure tube rolled joints. final report

Résumé du livre

Electrical and mechanical transients were used to simulate acoustic emission (ae) signals expected during a crack-growth experiment by temperature-pressure cycling of a pressure tube. electric noise simulated heater noise, while mechanical transients from pencil-lead breaks and ballpoint-pen impacts on a pressure tube, respectively simulated ae from crack growth and mechanical noise in an operating fuel channel. simulations were used, before cycling, to assess the method's capability to discriminate against noise, calibrate instruments for sensitivity, and interpret ae events observed during cycling. digital signal processing (dsp) techniques, using correlation and frequency analyses, were applied to digitized transients. results show that: (i) a spatial filter on the ae instrument provides about 60 db discrimination against extraneous electrical and mechanical noise, (ii) ae bursts from ballpoint-pen impacts and pencil-lead breaks, on a pressure tube, contain low (