Use of full-field measurements for understanding acoustic emission (AE) signals from 15CDV6 ESR steel specimens

One of the primary issues with acoustic emission (AE) technique is the lack of correlation of the AE signals with the quantitative mechanical behavior of any material and structure. In this paper, Digital Image Correlation (3D-DIC) is used as a complementary tool to support the AE observation for 15CDV6 ESR (electro slag refined) steel specimens. Towards this goal, standard surface cracked tensile (SCT) and plain tensile (PT) specimens were examined to understand their failure behavior. The surface cracks were generated on welds whereas the PT specimens were without any weld. Two parameters namely the centre crack opening displacement (CCOD) and the strain fields in the vicinity of the crack tips were correlated with the AE parameters to establish various stages of material degradation in SCT specimens. Similarly, in PT specimens AE signals corresponding to initiation of yielding and growth of an internal defect were identified correlating with the strains measured from DIC. The results indicate that integration of AE and DIC could be one of the favorable options for a comprehensive understanding of structural integrity and material degradation. (C) 2019 The Authors. Published by Elsevier B.V.