APPLICABILITY OF NEUBERS RULE TO THE ANALYSIS OF STRESS AND STRAIN CONCENTRATION UNDER CREEP CONDITIONS

A differential form of Neuber's rule, originally proposed by M. Chaudo nneret, has been formulated for a generic viscoplastic notch problem, making extensive use of suitably normalised stress, strain and time. I t has been shown that the stress-strain history at the root of a notch in a viscoplastic body can be determined directly from the elastic re sponse, provided far-field viscoplastic strains can be neglected. Neub er's rule has also been applied to the more general cases of stress an d strain concentration at notches under (i) nominal creep conditions ( constant nominal stress) and (ii) stress relaxation (constant nominal strain). Predictions are in good agreement with results from finite el ement analyses. Stress and strain concentration factors have been obse rved to approach stationary values after long-time loading. The statio nary stress concentration factor under stress relaxation falls below t hat under nominal Creep conditions.