scholarly journals Effect of the 3rd Dimension within the Representative Volume Element (RVE) on Damage Initiation and Propagation during Full-Phase Numerical Simulations of Single and Multi-Phase Steels

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 42
Author(s):  
Faisal Qayyum ◽  
Muhammad Umar ◽  
Sergey Guk ◽  
Matthias Schmidtchen ◽  
Rudolf Kawalla ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Representative Volume Element ◽  
Volume Element ◽  
Ductile Damage ◽  
Model Parameters ◽  
Damage Initiation ◽  
Representative Volume ◽  
Multi Phase ◽  
Local Results ◽  
Global And Local

In this research, the effect of 2D and 3D Representative Volume Element (RVE) on the ductile damage behavior in single-phase (only ferrite) and dual-phase (ferrite and martensite) steels is analyzed. Physical and fitting parameters of the constitutive model for bcc-ferrite and bcc-martensite phases are adapted from the already published work. Crystal plasticity (CP) based numerical simulations without damage consideration are run and, later, ductile damage criteria for the ferrite phase is defined for all cases. The results of the non-damage (-nD-) and damage (-D-) simulations are compared to analyze the global and local differences of evolving stresses and strains. It is observed that for the same model parameters defined in all cases, damage initiation occurs at the overall higher global strain in the case of 3D compared to 2D. Based on statistical data analysis, a systematic comparison of local results is carried out to conclude that the 3D RVEs provide better quantitative and qualitative results and should be considered for such full phase simulations. Whereas 2D RVEs are simple to analyze and provide appropriate qualitative information about the damage initiation sites.

Strength prediction of woven composite rings using progressive damage modeling

2020 ◽  
Vol 29 (6) ◽  
pp. 851-873
Author(s):  
H Khayyam Rayeni ◽  
AH Mazaheri ◽  
F Taheri-Behrooz
Keyword(s):  
Representative Volume Element ◽  
Stiffness Matrix ◽  
Volume Element ◽  
Progressive Damage ◽  
Equivalent Stiffness ◽  
Woven Composite ◽  
Damage Initiation ◽  
Plain Weave ◽  
Representative Volume ◽  
Composite Pipe

The ultimate failure of the woven composite pipes has been investigated using progressive damage modeling. The composite pipe specimens were made of (E) glass plain weave fabrics according to the ASTM D2290 standard. The hoop strength of these specimens has been obtained from the tensile tests. The damage initiation and propagation of composite pipe have been predicted by a numerical multi-scale method. For this purpose, the damage of the yarns and resin of the plain weave laminate was investigated by modeling a representative volume element. Then, the macroscopic stresses and strains of the representative volume element were calculated to obtain the equivalent stiffness matrix using suitable boundary conditions. Then, the mechanical properties of the laminate and material properties degradation coefficients were derived by this equivalent stiffness matrix. Hashin and Von Mises failure criteria were utilized in USDLFD subroutine to predict the damage initiation of the yarn and resin in the representative volume element, respectively. The sudden degradation method has been used to investigate the damage propagation in these constituents. Then, the woven composite ring was modeled in ABAQUS software and its ultimate strength was predicted by UMAT subroutine using obtained degradation coefficients of the representative volume element from the previous step. Finally, the numerical results were compared with the experimental data which show good agreement between the results.

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.

Effective use of cohesive zone-based models for the prediction of progressive damage at the fiber/matrix scale

2016 ◽  
Vol 51 (5) ◽  
pp. 649-669 ◽  
Author(s):  
Michael K Ballard ◽  
John D Whitcomb
Keyword(s):  
Representative Volume Element ◽  
Strain Energy Release ◽  
Initial Guess ◽  
Volume Element ◽  
Dissipated Energy ◽  
Model Parameters ◽  
Cohesive Elements ◽  
Representative Volume ◽  
Failure Properties ◽  
Fiber Matrix

The onset and growth of damage in fiber/matrix composites under transverse loads were modelled using cohesive elements and representative volume elements of randomly arranged fibers. Switching between iterative schemes, using an appropriate tolerance and load increment size, and using an extrapolated solution as an initial guess for load increments led to over an order of magnitude reduction in the solution time. The effect of several model parameters on the failure properties for the next larger scale was studied. The crack path did exhibit a dependence on the mesh, but the RVE strength and amount of dissipated energy in the representative volume element did not vary more than 4% for any of the mesh refinements considered. Periodic boundary conditions minimally interfered with the localization of damage when the localized band of damage did not extend across the entire RVE or when the damage naturally localized parallel to a boundary or diagonal of the representative volume element. A local method for quantifying the energy dissipated within the representative volume element was proposed, which provides an improved accuracy and flexibility. An approach to precisely define the dominant crack was given, which allowed the energy dissipate diffusely and along the dominant crack to be separated. It was shown that the predicted critical strain energy release rate for the representative volume element was sensitive to the representative volume element unless the diffusely dissipated energy was accounted for separately. The proposed technique for calculating failure properties within a multiscale framework has the potential to be applied to other damage models.

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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