[SY-C12] Modeling the interaction between martensitic phase transformations and dislocation dynamics
Two of the most important deformation mechanisms in TRIP-Steel are the martensitic phase transformations (MT) and elastic/plastic deformation due to the motion of dislocations. Martensitic phase transformations are desirable because they enhance the strength of TRIP-steels, however, dislocations can lower the strength of the material. These two phenomena are strongly coupled due to their contributions of strain to the system, resulting in an effect on the final macroscopic properties of the material. Thus, both dislocations and phase transformations must be considered simultaneously when modeling TRIP-Steels.
While MD simulations are inherently able to treat both dislocations and MT, such simulations suffer from a high computational cost and, hence, are not able to reach relevant time scales. Phenomenological continuum models for plasticity can be coupled with phase field approaches for the MT and can reach larger time scales; they do not capture the dynamics of the dislocations.
In our model, the dynamics of dislocations is described by a continuum dislocation dynamics (CDD) model, where instead of individual dislocations, a dislocation density is considered. This approach reduces the computational cost and enables the modeling of larger length scales. We use a coupled CDD/phase field approach to study the interaction of dislocation plasticity and the martensitic phase transformations. Our main focus is on the influence of different initial values and on the history dependence of the material. This will allow us to discuss, among others, what happens to dislocations in regions that undergo a MT - an information of big importance for continuum models operating on larger length scales.
While MD simulations are inherently able to treat both dislocations and MT, such simulations suffer from a high computational cost and, hence, are not able to reach relevant time scales. Phenomenological continuum models for plasticity can be coupled with phase field approaches for the MT and can reach larger time scales; they do not capture the dynamics of the dislocations.
In our model, the dynamics of dislocations is described by a continuum dislocation dynamics (CDD) model, where instead of individual dislocations, a dislocation density is considered. This approach reduces the computational cost and enables the modeling of larger length scales. We use a coupled CDD/phase field approach to study the interaction of dislocation plasticity and the martensitic phase transformations. Our main focus is on the influence of different initial values and on the history dependence of the material. This will allow us to discuss, among others, what happens to dislocations in regions that undergo a MT - an information of big importance for continuum models operating on larger length scales.