ACOUSTIC-EMISSION DURING DEFORMATION AND CRACK LOADING IN STRUCTURAL-STEELS

Results of extensive acoustic emission studies are given for flawed and unflawed specimens of low carbon structural steels tested at different loading rates. For the tensile unflawed tests, a detailed discussion of the stress dependence of emission activity below yield is presented. This analysis indicates that count rate per unit volume is directly proportional to loading rate, with the constant of proportionality generally dependent on the applied stress. Using this finding in the description of deformation around the crack tip, an analytical relationship between acoustic emission characteristics and fracture mechanics parameters is proposed. At low stress intensity levels there is a promising agreement between theoretical predictions and experimental data.