| Popis: |
One of the complex inelastic behavioural phenomena that structural materials may exhibit when subjected to specific thermomechanical loading histories is Dynamic Strain Ageing (DSA). The modeling of DSA within the context of unified theories of viscoplasticity is studied in this paper. In particular, an algorithm is proposed to include DSA modeling capability in Chaboche’s theory. In doing so, use is made of the so-called “correction function” proposed by other investigators. A rather general form of such a function is adopted, and included in the theory in three different ways. It is found that the simplest and most appropriate way to model DSA is to introduce the correction function into the initial value of the isotropic hardening stress, Do. As such, Do is made to change with the imposed strain rate within the range of negative strain-rate sensitivity, and is held constant otherwise. |
