Staging of a localized plastic deformation during extension of D16AT alloy specimens based on the data of acoustic emission, mapping of surface deformations, and strain gauging. 1. Specimens with holes of different diameters

The development of deformations and fracturing in D16AT alloy specimens with central holes was investigated using a combination of the acoustic emission, surface-deformation mapping, and strain-gauging methods. Three characteristic deformation-development stages were selected. Changes in the durations of the characteristic stages obtained from the data of the analysis of all informative parameters indicate that the specific duration gradually increases for the second stage and remains constant for the third stage. It was shown that the staging approach in studies and testing of deformations and fractures is quite informative and mutually complementary in the case of low concentrations of stresses. However, the durations of stages that were revealed on the basis of data from recording of informative parameters may be appreciably different. This is associated with the sensitivity of each method to deformation flaws at each scale level and the sensitivity/resolution of the recording equipment.