LENGTH CHANGES DURING LARGE STRAIN REVERSE TORSION

Large strain reverse torsion of FCC polycrystalline circular solid bars and tubes is investigated numerically for free-end boundary conditions. A rate-sensitive crystal plasticity model is used in the analyses. Results are presented in terms of the predicted torque response and the axial elongation. The simulations predict that, upon reversal of the twisting direction, the specimen first shortens before continuing to elongate. The influence of the wall thickness on this Swift effect is emphasized.KEY WORDSCrystal plasticity, large strain plasticity, texture development, reverse torsion, Swift effect.