DETERMINATION OF CRACK-GROWTH RATE USING ACOUSTIC-EMISSION SIGNALS

A method is presented for determining the longevity of samples and articles containing cracks which are under static loading. Cases of brittle failure and failure in the presence of a zone of plastic deformation in the region of the crack tip are examined. It is shown that during brittle failure, growth occurs by a series of jumps. The time between these jumps decreases rather rapidly with increase in the number of jumps. In the presence of a plastic deformation zone the crack jumps are more significant, but the time between them decreases very slowly.