Using spectral-based representative volume element crystal plasticity simulations to predict yield surface evolution during large scale forming simulations

2020 ◽  
Vol 277 ◽  
pp. 116449 ◽  
Author(s):  
Fengbo Han ◽  
Martin Diehl ◽  
Franz Roters ◽  
Dierk Raabe
Keyword(s):  
Representative Volume Element ◽  
Crystal Plasticity ◽  
Yield Surface ◽  
Large Scale ◽  
Volume Element ◽  
Surface Evolution ◽  
Representative Volume ◽  
Forming Simulations

Crystal Plasticity Simulation of the Bauschinger Effect of Polycrystalline AA7075 through a Texture-Based Representative Volume Element Model

2014 ◽  
Vol 553 ◽  
pp. 22-27
Author(s):  
Ling Li ◽  
Lu Ming Shen ◽  
Gwénaëlle Proust
Keyword(s):  
Finite Element ◽  
Representative Volume Element ◽  
Crystal Plasticity ◽  
Bauschinger Effect ◽  
Voronoi Tessellation ◽  
Strain Curve ◽  
Element Model ◽  
Volume Element ◽  
Model Parameters ◽  
Representative Volume

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.

Crystal plasticity modeling of grain refinement in aluminum tubes during tube cyclic expansion-extrusion

2016 ◽  
Vol 232 (6) ◽  
pp. 481-494 ◽  
Author(s):  
A Babaei ◽  
MM Mashhadi ◽  
F Mehri Sofiani
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Representative Volume Element ◽  
Crystal Plasticity ◽  
Element Model ◽  
Volume Element ◽  
Deformation History ◽  
Crystal Plasticity Finite Element ◽  
Representative Volume ◽  
History Of

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.

scholarly journals Investigation of the scale effect and the concept of a representative volume element of rocks in relation to porosity

Georesursy ◽  
2020 ◽  
Vol 22 (4) ◽  
pp. 55-69
Author(s):  
Damir I. Khassanov ◽  
Marat A. Lonshakov
Keyword(s):  
Representative Volume Element ◽  
Scale Effect ◽  
Large Scale ◽  
Sampling Technique ◽  
Volume Element ◽  
Carbonate Reservoirs ◽  
Pore Network Model ◽  
Standard Size ◽  
The Core ◽  
Representative Volume

The article discusses the concepts of upscaling, the representative volume element (RVE) of the geological environment in relation to porosity from the point of view of the theory of structured continuum. The manifestation of the large-scale effect of porosity in terrigenous and carbonate reservoirs has been studied. The analysis of domestic and foreign methods of core sampling was carried out using the example of the Schlumberger company to study the porosity and permeability of the core in petrophysical laboratories and calculate the RVE of rock samples according to the porosity values ​​determined by analyzing the pore-network model, liquid saturation, nuclear magnetic resonance and X-ray computed tomography, as well as the gas-volumetric method. The features and reasons for the manifestation of the large-scale effect of porosity in heterogeneous carbonate reservoirs have been studied. Methods for quantitative assessment of the anisotropy of rocks in the study of heterogeneity of rocks are considered. The necessity of taking into account the scale effect of porosity in the analysis of the correlation dependence “core - geophysical well logging”, established from the porosity data for both terrigenous and carbonate sections. The feasibility of using a core with a diameter of 60–100 mm and standard-size samples is considered when comparing laboratory values ​​of porosity and porosity values ​​determined from logging data. A study of direct and indirect petrophysical methods for determining the porosity of core samples was carried out when solving the same problems to identify the minimum representative volume of a core sample. It has been established that direct methods are the most effective in terms of time and financial costs for the prompt calculation of porosity coefficients for specimens with a diameter and height of 30–100 mm. The analysis of the porosity data ultimately made it possible to study the manifestation of the scale effect of porosity with a change in the sample size. A detailed analysis of published works will allow in the future to develop our own effective sampling technique for determining the RVE of the core interval as applied to porosity.

scholarly journals Representative volume element based micromechanical modelling of rod shaped glass filled epoxy composites

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Aanchna Sharma ◽  
Yashwant Munde ◽  
Vinod Kushvaha
Keyword(s):  
Representative Volume Element ◽  
Poisson’S Ratio ◽  
Volume Fraction ◽  
Tensile Modulus ◽  
Volume Element ◽  
Poisson's Ratio ◽  
Epoxy Composites ◽  
Micromechanical Modeling ◽  
Representative Volume ◽  
Shaped Glass

AbstractIn this study, Representative Volume Element based micromechanical modeling technique has been implemented to assess the mechanical properties of glass filled epoxy composites. Rod shaped glass fillers having an aspect ratio of 80 were used for preparing the epoxy composite. The three-dimensional unit cell model of representative volume element was prepared with finite element analysis tool ANSYS 19 using the periodic square and hexagonal array with an assumption that there is a perfect bonding between the filler and the epoxy matrix. Results revealed that the tensile modulus increases and Poisson’s ratio decreases with increase in the volume fraction of the filler. To study the effect of filler volume fraction, the pulse echo techniques were used to experimentally measure the tensile modulus and Poisson’s ratio for 5% to 15% volume fraction of the filler. A good agreement was found between the RVE based predicted values and the experimental results.

Localization simulation of forming-induced residual stresses of composite using prescribed boundary

2021 ◽  
pp. 073168442094118
Author(s):  
Qi Wu ◽  
Hongzhou Zhai ◽  
Nobuhiro Yoshikawa ◽  
Tomotaka Ogasawara ◽  
Naoki Morita
Keyword(s):  
Residual Stresses ◽  
Representative Volume Element ◽  
Computational Cost ◽  
Volume Element ◽  
Thermoplastic Composite ◽  
Structural Deformation ◽  
Element Analysis ◽  
Micro Scale ◽  
Representative Volume ◽  
Localization Approach

A novel localization approach that seamlessly bridges the macro- and micro-scale models is proposed and used to model the forming-induced residual stresses within a representative volume element of a fiber reinforced composite. The approach uses a prescribed boundary that is theoretically deduced by integrating the asymptotic expansion of a composite and the equal strain transfer, thus rendering the simulation setting to be easier than conventional approaches. When the localization approach is used for the finite element analysis, the temperature and residual stresses within an ideal cubic representative volume element are precisely simulated, given a sandwiched thermoplastic composite is formed under one-side cooling condition. The simulation results, after being validated, show that the temperature gradient has an impact on the local residual stresses, especially on the in-plane normal stress transverse to the fiber, and consequently, influences the structural deformation. This newly designed localization approach demonstrates the advantages of enhanced precision and reduced computational cost owing to the fast modeling of the finely meshed representative volume element. This is beneficial for a detailed understanding of the actual residual stresses at the micro-scale.

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