Ratchetting under tension-torsion loadings: experiments and modelling

This paper is concerned with the mechanical behaviour of 316 austenitic sta inless steel under multiaxial loadings and particular attention is paid to ratchetting under tension-torsion non-proportional loadings. First, a serie s of uniaxial tests and biaxial tests has been carried out in order to cali brate five different cyclic plasticity models based on an isotropic hardeni ng rule and a non-linear kinematic hardening rule. It is shown that this cl ass of models gives quite good agreement between the experimental and numer ical results. Second, another series of ratchetting tests has been carried out under tension-torsion loadings in order to test the prediction capaciti es of the previous models. It is shown that whereas the models have been ca librated with similar loading paths, four of the five selected models give poor predictions. (C) 2000 Elsevier Science Ltd. All rights reserved.