Roles of Incompatibility Tensor on Lath Block in FTMP

Abstract

FTMP concept is applied to computationally fabricate complex microstructured samples to be further utilized in various deformation analyses based on, e.g., FEM. Here, we focus on the process of modeling single lath-block structures provided the corresponding eigenstrain distributions based on the Bain lattice correspondence is initially introduced. One of the keys for the lath-block modeling is the development of misorientation across the lath boundaries, together with the attendant internal stress fields. FTMP-based approach exhibits spontaneous evolution of such misorientation when substantial contribution of the incompatibility tensor is introduced in the hardening law. Here we decompose the incompatibility tensor into (a)pure deformation and pure rotation, (b)edge and screw, and (c)spherical (isotropic) and deviatoric components, respectively, to examine the mechanisms for the misorientation developments.Analyses are conducted using two basic models for a single lath block structure. Demonstrated for (a) is that the pure deformation part shows relatively larger contributions to the misorientation developments, while, for (b), dominant contributions of the screw component are confirmed. For (c), on the other hand, the weighted spherical part is shown to have weak but basically the same contribution.