An RVE-Based Study of the Effect of Martensite Banding on Damage Evolution in Dual Phase Steels

Abstract

The intent of this work is to numerically investigate the effect of second phase morphology on damage evolution characteristics of dual-phase (DP) steels. A strain gradient enhanced crystal plasticity framework is used in order to capture the deformation heterogeneity caused by lattice orientations and microstructural size effects. The investigation is focused on two different martensite distributions (banded and random) that are relevant for industrial applications. The effects of martensite morphology are compared by artificially generated 2D plane strain microstructures with initial void content. The Representative volume elements (RVEs) are subjected to tensile deformation imposed by periodic boundary conditions. Evolution of voids are analyzed individually as well as a whole and characterized with respect to average axial strain. It is found that during stretching voids exhibit varying evolution characteristics due to generation of inhomogeneous strain fields within the structure. The behavior of individual voids shows that the stress-state surrounding the void is different from the imposed far field macroscopic stress-state. The voids at the ferrite martensite interface and in ferrite grains of the randomly distributed martensite grow more than in the banded structure. On the other hand, voids formed by martensite cracking growth shows an opposite trend.

Prediction of texture-induced plastic anisotropy in AA6014-T4 aluminium sheets utilising two different crystal plasticity-based constitutive models

“…The first crystal plasticity-based constitutive model is based on the numerical framework presented in Kalidindi et al [9] and is fully described in Pagenkopf [10]. A detailed summary of the second crystal plasticity-based constitutive model is given in Aşık et al [11]. Hence, the following section focuses on the common fundamental equations of both formulations and their differences with respect to the flow rule (ratedependent/rate-independent) and hardening law (phenomenological/physical-based).…”

Response of 2d and 3d Crystal Plasticity Models Subjected to Plane Strain Condition

“…A rate-independent finite strain crystal plasticity model [15] is employed as the material model at each integration point in the finite element simulations in Abaqus/Standard. Rate-independent formulation avoids adding any artificial numerical rate sensitivity and contributes to addressing the discrepancy of the macroscopic material response exposed to local plane strain condition in 2D and averaged plane strain condition in 3D concisely.…”

“…( 5) denotes the balance between the generation of dislocations by the Frank-Read mechanism and dislocation annihilation. For the details of the implementation of the numerical solution to the stress update algorithm in this model, one can refer to [15].…”

“…Determination of the size of 2D RVE. Ten stochastic generations are used per number of grains per VE edge(3,6,9,12,15). Average true stress-true strain curves for all VEs are presented in the loading direction.…”

Influence of Grain Orientation and Grain Boundary Features on Local Stress State of Cu-8Al-11Mn Alloy Investigated Using Crystal Plasticity Finite Element Method

“…Therefore, CPFEM was more suitable for studying the stress formation mechanism between grains. Until now, CPFEM has been widely used to predict grain orientation rotation [ 18 , 19 , 20 ], the inhomogeneity of plastic strain and local stress [ 21 , 22 ], and grain orientation distribution [ 23 , 24 , 25 ] during deformation. A systematical evaluation of the effect of grain orientations and grain boundary features on the local stress state of a Cu-Al-Mn alloy using CPFEM will provide theoretical guidance for understanding the impact of grain features on SE properties at the grain scale.…”