A theoretical evaluation of plasticity hardening algorithms for nonproportional loadings
For incremental plasticity algorithms, a \(\pi\)-circle loading path in deviatoric stress space was identified as a severe test for the algorithms. A closed form solution can be obtained for this loading path, so that these phenomena cannot be attributed to numerical errors. While this loading is highly idealized, analogous results are also noted for 90 degree out-of-phase tension-torsion. Multiple surface and the associated two-surface models with a stationary bounding surface are shown to exhibit both theoretical and numerical problems for the severe cyclic loading under consideration. It is established that the Armstrong-Frederick class of models demonstrates a diminished sensitivity to model parameters. Finally, single-valued stress strain representations for both severe nonproportional loading paths are investigated.
single-valued stress strain representations
scientific article; zbMATH DE number 1004514
scientific article