Microstructural modelling of dual-phase steelsthrough polycrystalline plasticity at RVE level

Güngör, Gönül Öykü
In this work the plasticity, localization and the damage behavior of dual phase steels are investigated through both J2 and crystal plasticity frameworks. For this purpose, Voronoi based Representative Volume Elements (RVE) are created with different martensite volume fractions, which are studied at different constant triaxiality values. The micromechanical and the macroscopic constitutive responses are analyzed in detail for considering various loading conditions and microstructural parameters. The results are discussed in comparison to the ones in the literature and the work is concluded with remarks and outlook.


Modeling of localization and necking in dual phase steels through polycrystalline plasticity
Çakmak, Serhat Onur.; Yalçınkaya, Tuncay; Department of Aerospace Engineering (2020)
In this thesis, the effect of ferrite crystallographic orientation distribution and other microstructural parameters such as martensite morphology, martensite volume fraction, and ferrite grain size on the plastic deformation, localization, and the necking behavior of dual-phase steels are investigated. Two different type of finite element models, i.e. full size micron-scale polycrystalline samples and polycrystalline Representative Volume Element (RVEs) are built through Voronoi tessellation. Local crystal...
A Micromechanics Based Numerical Investigation of Dual Phase Steels
Yalçınkaya, Tuncay; Çakmak, Serhat Onur (Elsevier BV; 2019-01-01)
The aim of this paper is to investigate the effects of microstructural parameters such as the volume fraction, morphology and spatial distribution of the martensite phase and the grain size of the ferrite phase on the plasticity and localized deformation of dual-phase (DP) steels. For this purpose, Voronoi based representative volume elements (RVEs) are subjected to proportional loading with constant stress triaxility. Two alternative approaches are employed in a comparative way to model the plastic respons...
Morphology and Grain Orientation Dependent Localization and Necking in Dual-phase Steels
Çakmak, Serhat Onur; Yalçınkaya, Tuncay (2019-01-01)
This paper studies the plastic deformation, localization and the necking behavior of polycrystalline dual phase (DP) steels, with different martensite volume fractions, and ferrite orientation distributions, through crystal plasticity finite element method. The grain structure of the full size micron-scale polycrystalline samples is built through Voronoi tesselation and the specimens are deformed under uniaxial loading condition. For the modelling of martensite phase J2 plasticity with isotropic hardening i...
Liquid crystal-templated synthesis of polymeric microparticles with complex nanostructures
Akdeniz, Burak; Büküşoğlu, Emre; Department of Chemical Engineering (2019)
Liquid crystals (LC), when combined with photolithography, enable synthesis of microparticles with two- and three-dimensional shapes and internal complexities. We prepared films of nematic LCs using mixtures of reactive (RM257) and non-reactive mesogens (E7) with controlled alignment of LCs at the confining surfaces, photopolymerized the RM257 using a photomask, and then extracted the unreacted mesogens to yield polymeric microparticles. The extraction resulted in a controlled anisotropic shrinkage with an ...
Characterization of dual phase steels by using magnetic barkhausen noise analysis
Kaplan, Mücahit; Gür, Cemil Hakan; Department of Metallurgical and Materials Engineering (2006)
The aim of this work is to nondestructively characterize the industrial dual phase (ferritic-martensitic) steels (DPS) by the Magnetic Barkhausen Noise (MBN) method. By quenching of AISI 8620 steel specimens having two different starting microstructures, from various intercritical annealing temperatures (ICAT) in the ferrite-austenite region, the microstructures consisting of different volume fractions of martensite and morphology have been obtained. The microstructures, strength properties and hardness val...
Citation Formats
G. Ö. Güngör, “Microstructural modelling of dual-phase steelsthrough polycrystalline plasticity at RVE level,” Thesis (M.S.) -- Graduate School of Natural and Applied Sciences. Aerospace Engineering., Middle East Technical University, 2019.