Multi Scale Modeling of Microstructure Evolution Induced Anisotropy in Metals

This paper presents two crystal plasticity based computational constitutive models for the intrinsic formation of plastic microstructure during monotonic loading and its altered evolution under strain path changes in metal forming operations. The formation step is modeled via a non-convex strain gradient crystal plasticity framework which could simulate the intrinsic development of the plastic microstructures. The evolution under strain path changes is modeled via phenomenologically based constitutive equations incorporated into crystal plasticity framework. The latter is capable of simulating the transient anisotropy effects (e.g. cross hardening, Bauschinger effect) depending on the change in the strain path. The paper discusses the unification of such models for the continuous modeling of microstructure formation and evolution processes.
Key Engineering Materials


Intrinsic and Statistical Size Effects in Microforming
Yalçınkaya, Tuncay; Simonovski, Igor; ÖZDEMİR, İZZET (2017-04-28)
This paper analyzes the intrinsic (grain size dependent) and the statistical (grain number and orientation distribution dependent) size effects of micron level polycrystalline metallic specimens under plastic deformation through a strain gradient crystal plasticity framework. The macroscopic and local behavior of specimens from very limited number of grains to high number of grains are studied and the results are discussed in detail taking into account different boundary conditions.
Covalent and noncovalent functionalization of pristine and defective graphene by cyclohexane and dehydrogenated derivatives
Sayin, Ceren Sibel; Toffoli, Daniele; Toffoli, Hande (2015-10-01)
The interaction of cyclohexane (C6H12), cyclohexyl (C6H11*) and cyclohexene (C6H10) with both pristine and defective graphene (single vacancy and a carbon adatom), is systematically investigated within the density functional theory framework. C6H12 physisorbs on both pristine and defective graphene while C6H10 chemisorbs on graphene in the presence of an adatom. The C6H11* radical binds covalently with the graphene substrate in all adsorption geometries considered.
Polycrystalline plasticity modeling of anisotropic grain structures and statistical size effect in metallic alloys
Orhun, Bulut; Yalçınkaya, Tuncay; Department of Aerospace Engineering (2022-6-14)
In this thesis, two important microstructural phenomena affecting the plastic behavior of metallic materials are addressed through a local crystal plasticity modeling framework. Initially the influence of anisotropic grain structure developing during various forming procedures and additive manufacturing processes is studied following a multiscale modeling strategy, where Representative Volume Elements (RVEs) are analyzed under axial loading conditions. Macroscopic response of different degrees of anisotropi...
Micromechanical Modelling of Size Effects in Microforming
Yalçınkaya, Tuncay; SIMONOVSKI, IGOR; ÖZDEMİR, İZZET (2017-09-01)
This paper deals with the micromechanical modelling of the size dependent mechanical response of polycrystalline metallic materials at micron scale through a strain gradient crystal plasticity framework. The model is implemented into a Finite Element software as a coupled implicit user element subroutine where the plastic slip and displacement fields are taken as global variables. Uniaxial tensile tests are conducted for microstructures having different number of grains with random orientations in plane str...
Plastic slip patterns through rate-independent and rate-dependent plasticity
Lancioni, Giovanni; Yalçınkaya, Tuncay (2014-05-09)
Plastic deformation induces various types of dislocation microstructures at different length scales, which eventually results in a heterogeneous deformation field in metallic materials. Development of such structures manifests themselves as macroscopic hardening/softening response and plastic anisotropy during strain path changes, which is often observed during forming processes. In this paper we present two different non-local plasticity models based on non-convex potentials to simulate the intrinsic rate-...
Citation Formats
T. Yalçınkaya, “Multi Scale Modeling of Microstructure Evolution Induced Anisotropy in Metals,” Key Engineering Materials, pp. 2388–2399, 2013, Accessed: 00, 2020. [Online]. Available: