scholarly journals Effect of 3D Representative Volume Element (RVE) Thickness on Stress and Strain Partitioning in Crystal Plasticity Simulations of Multi-Phase Materials

Crystals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 944 ◽  
Author(s):  
Faisal Qayyum ◽  
Aqeel Afzal Chaudhry ◽  
Sergey Guk ◽  
Matthias Schmidtchen ◽  
Rudolf Kawalla ◽  
...  

Crystal plasticity simulations help to understand the local deformation behavior of multi-phase materials based on the microstructural attributes. The results of such simulations are mainly dependent on the Representative Volume Element (RVE) size and composition. The effect of RVE thickness on the changing global and local stress and strain is analyzed in this work for a test case of dual-phase steels in order to identify the minimal RVE thickness for obtaining consistent results. 100×100×100 voxel representative volume elements are constructed by varying grain size and random orientation distribution in DREAM-3D. The constructed RVEs are sliced in depth up to 1, 5, 10, 15, 20, 25, 30, 40, and 50 layers to construct different geometries with increasing thickness. Crystal plasticity model parameters for ferrite and martensite are taken from already published data and assigned to respective phases. Although the global stress/strain behavior of different RVEs is similar (<5% divergence), the local stress/strain partitioning in RVEs with varying thickness and grain size shows a considerable variation when statistically compared. It is concluded that two-dimensional (2D) RVEs can be used for crystal plasticity simulations when global deformation behavior is of interest. Whereas, it is necessary to consider three-dimensional (3D) RVEs, which have a specific thickness and number of grains for determining stabilized and more accurate local deformation behavior. This estimation will help researchers in optimizing the computation time for accurate mesoscale simulations.

2015 ◽  
Vol 651-653 ◽  
pp. 570-574 ◽  
Author(s):  
Akinori Yamanaka

The plastic deformation behavior of dual-phase (DP) steel is strongly affected by its underlying three-dimensional (3D) microstructural factors such as spatial distribution and morphology of ferrite and martensite phases. In this paper, we present a coupled simulation method by the multi-phase-field (MPF) model and the crystal plasticity fast Fourier transformation (CPFFT) model to investigate the 3D microstructure-dependent plastic deformation behavior of DP steel. The MPF model is employed to generate a 3D digital image of DP microstructure, which is utilized to create a 3D representative volume element (RVE). Furthermore, the CPFFT simulation of tensile deformation of DP steel is performed using the 3D RVE. Through the simulations, we demonstrate the stress and strain partitioning behaviors in DP steel depending on the 3D morphology of DP microstructure can be investigated consistently.


2014 ◽  
Vol 553 ◽  
pp. 22-27
Author(s):  
Ling Li ◽  
Lu Ming Shen ◽  
Gwénaëlle Proust

A texture-based representative volume element (TBRVE) model is developed for the three-dimensional crystal plasticity (CP) finite element simulations of the Bauschinger effect (BE) of polycrystalline aluminium alloy 7075 (AA7075). In the simulations, the grain morphology is created using the Voronoi tessellation method with the material texture systematically discretised from experiment. A modified CP constitutive model, which takes into account the backstress, is used to simulate the BE during cyclic loading. The model parameters are calibrated using the first cycle stress-strain curve and used to predict the mechanical response to the cyclic saturation of AA7075. The results indicate that the proposed TBRVE CP finite element model can effectively capture the BE at the grain level.


2020 ◽  
Vol 42 (4) ◽  
pp. 427-434
Author(s):  
Duc-Chinh Pham

Our major new results and the previous ones on the bounds for elastic random polycrystals, and most advanced 3D finite element results for random 3D Voronoi polycrystals are resumed and analysed (together for the first time). Recently obtained numerical Dirichlet and Neumann simulation results for the effective elastic moduli of a large 10000-grain-size random Voronoi polycrystal representative volume element (RVE) for a number of triclinic and monoclinic base crystals (Mursheda and Ranganathan, 2017) are compared critically with the bounds on the moduli. Though major parts within the simulation results fall within the bounds of Pham (2011), some Dirichlet upper estimates still lie outside the bounds. Many more RVEs are needed to represent the Voronoi polycrystal on the same RVE-size-level, and larger RVEs are needed for checking the convergence and comparisons with the bounds.


2019 ◽  
Vol 794 ◽  
pp. 71-77 ◽  
Author(s):  
Truong Duc Trinh ◽  
Takeshi Iwamoto

TRIP steel shows excellent mechanical properties such as greatly high strength, ductility and toughness by means of the appropriate combination of the strain-induced martensitic transformation (SIMT) behavior and the deformation behavior of each phase at crystal scale. In the past, the effect of grain size in the austenite on the deformation behavior of TRIP steel is investigated by introducing the grain size into a generalized model for the kinetics of SIMT. In order to validate the size-dependent kinetics modelling, it is necessary to simulate the deformation and SIMT behavior of the polycrystalline for the different grain size at the crystal scale. This study focuses on an investigation of SIMT behavior in polycrystalline TRIP steel by finite element simulation. The constitutive formula for monocrystalline TRIP steel including transformation strain in each variant system derived on the basis of the continuum crystal plasticity theory is applied. For the polycrystalline model, Voronoi tessellation is employed. The deformation behavior with a patterning process of martensitic phase in two different numbers of grains with initial crystal orientations for describing the deformation-related length scale is simulated under plane strain condition with two planar slip systems by a cellular automata approach.


Author(s):  
A Babaei ◽  
MM Mashhadi ◽  
F Mehri Sofiani

In the present study, a crystal plasticity finite element model was developed for simulating the microstructure evolution and grain refinement during tube cyclic expansion-extrusion as a severe plastic deformation method for tubular materials. A new approach was proposed for extracting the real deformation history of a representative volume element during severe plastic deformation methods. The deformation history of a representative volume element during four cycles of tube cyclic expansion-extrusion was extracted by the proposed approach. Then, in a crystal plasticity finite element model, the deformation history was applied to a two-dimensional polycrystalline representative volume element with randomly assigned crystalline orientations. The intergranular interactions between grains and the intragranular orientation gradients were successfully simulated by the crystal plasticity finite element model. The distribution of misorientation angles, the evolution of grain boundaries, and the achieved average grain size after different cycles of tube cyclic expansion-extrusion were investigated by the crystal plasticity finite element model. On the other hand, ultrafine grained aluminum tubes were processed by four cycles of tube cyclic expansion-extrusion and the grain size of the processed tubes was studied by scanning electron microscopy observations and X-ray diffraction analyses. The experimental and predicted (by crystal plasticity finite element model) average grain sizes were compared.


2017 ◽  
Vol 20 (3) ◽  
pp. 311-323 ◽  
Author(s):  
M. Diehl ◽  
D. An ◽  
P. Shanthraj ◽  
S. Zaefferer ◽  
F. Roters ◽  
...  

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