Notch Stress and Strain Estimation Considering Multiaxial Constraint 930401

The uniaxial cyclic stress-strain curve is frequently used in fatigue analysis of stress concentrations, or notches, under unidirectional loading (tension or bending). However, constraint on transverse strain often causes considerable notch root multiaxiality, even when nominal stresses are uniaxial. A straightforward technique is developed for correcting the uniaxial stress-strain curve to explicitly account for notch root multiaxiality. The corrected curve is then used with a conventional Neuber's Rule analysis to more accurately estimate the state of stress and strain within a notch. Results agree favorably with elastic-plastic finite element results and limited experimental data from a shaft with circumferential notches in bending or torsion. Numerical results from the proposed approach were also in agreement with finite element predictions from a round bar with a through hole in tension.