scholarly journals Additive Manufacturing of Cementitious Materials by Selective Paste Intrusion: Numerical Modeling of the Flow Using a 2D Axisymmetric Phase Field Method

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5024
Author(s):  
Alexandre Pierre ◽  
Daniel Weger ◽  
Arnaud Perrot ◽  
Dirk Lowke
Keyword(s):  
Numerical Modeling ◽  
3D Printing ◽  
Cement Paste ◽  
Phase Field ◽  
Numerical Approach ◽  
Cementitious Materials ◽  
Field Method ◽  
Phase Field Method ◽  
Shape Accuracy ◽  
Cement Pastes

The 3D printing of concrete has now entered a new era and a transformation of the construction sector is expected to reshape fabrication with concrete. This work focuses on the selective paste intrusion method, which consists of bonding dry particles of aggregate with a cement paste. This innovative technique could lead to the production of very precise component for specific applications. The main obstacle to tackle in order to reach a high shape accuracy of high mechanical performances of 3D printing elements by selectively activating the material is the control of the distribution of the cement paste through the particle bed. With the aim to better understand the path followed by the solution as it penetrates a cut-section of the granular packing, two-dimensional numerical modeling is carried out using Comsol software. A phase-field method combined with a continuous visco-plastic model has been used to study the influence of the average grain diameter, the contact angle, and the rheological properties of cement pastes on the penetration depth. We compare the numerical modeling results to existing experimental results from 3D experiments and a one-dimensional analytical model. We then highlight that the proposed numerical approach is reliable to predict the final penetration of the cement pastes.

scholarly journals A mesoscale numerical approach to predict damage behavior in concrete basing on phase field method

2021 ◽  
Author(s):  
Nguyen Hoang Quan ◽  
Tran Bao Viet ◽  
Nguyen Thanh Tung
Keyword(s):  
Phase Field ◽  
Crack Nucleation ◽  
Crack Density ◽  
Numerical Procedure ◽  
Simulation Method ◽  
Numerical Approach ◽  
Field Method ◽  
Phase Field Method ◽  
Generation Process ◽  
Damage And Fracture

In this paper, we develop a numerical approach to simulate the 2D complex damage and fracture process of quasi-brittle concrete materials. Based on the phase field theory for the case of elastic isotropic multicomponent materials and the generation process based upon Monte Carlo’s simulation method, we construct a numerical  procedure to solve complex damage thermodynamic problems. The diffusive phase field variable obtained from this calculation can be used to represent the crack nucleation and propagation within 2D complex mesostructure. Some factors that affect the numerical result (type of crack density function and type of split decomposition of strain energy) are accounted to make the predictions more accurate for the case of concrete material. Some new numerical examples are provided to show the usefulness of the approach. 

Phase-Field Modeling of Morphological Change of Ferrite during Decomposition of Austenite in Fe-C Alloy

2007 ◽  
Vol 345-346 ◽  
pp. 935-938
Author(s):  
A. Yamanaka ◽  
Tomohiro Takaki ◽  
Yoshihiro Tomita
Keyword(s):  
Morphological Change ◽  
Phase Field ◽  
Numerical Approach ◽  
Field Method ◽  
Homogenization Method ◽  
Ferrite Phase ◽  
Phase Field Method ◽  
Element Analysis ◽  
Phase Field Simulation ◽  
Field Simulation

The integrated simulation model for microstructural design of Fe-C alloy using the phase-field method and the homogenization method is proposed. First, the phase-field simulation is performed to simulate the morphological change of the grain boundary ferrite to Widmanstätten ferrite. Then, in order to clarify the effects of the morphology of the ferrite phase on the micro- and macroscopic mechanical properties, the finite element analysis based on the homogenization method is conducted with the representative volume element obtained from the phase-field simulation. This numerical approach provides a powerful tool to investigate systematically the micro and macroscopic mechanical behavior with the morphological change of the ferrite phase in the Fe-C alloy.

The numerical modeling of cell freezing in binary solution under subcooling conditions

2019 ◽  
Vol 30 (6) ◽  
pp. 3005-3025
Author(s):  
Przemysław Smakulski ◽  
Sławomir Pietrowicz ◽  
Jun Ishimoto
Keyword(s):  
Numerical Modeling ◽  
Free Energy ◽  
Numerical Calculation ◽  
Phase Field ◽  
Field Method ◽  
Energy Functional ◽  
Phase Field Method ◽  
Phase Front ◽  
Content Type ◽  
Free Energy Functional

Purpose This paper aims to describe and investigate the mathematical models and numerical modeling of how a cell membrane is affected by a transient ice freezing front combined with the influence of thermal fluctuations and anisotropy. Design/methodology/approach The study consists of mathematical modeling, validation with an analytical solution, and shows the influence of thermal noises on phase front dynamics and how it influences the freezing process of a single red blood cell. The numerical calculation has been modeled in the framework of the phase field method with a Cahn–Hilliard formulation of a free energy functional. Findings The results show an influence scale on directional phase front propagation dynamics and how significant are stochastic thermal noises in micro-scale freezing. Originality/value The numerical calculation has modeled in the framework of the phase field method with a Cahn–Hilliard formulation of a free energy functional.

Theoretical phase-field-method-based model of the γ phase dissolution of base metals in duplex stainless steels

2021 ◽  
Vol 26 ◽  
pp. 102150
Author(s):  
Dong-Cho Kim ◽  
Tomo Ogura ◽  
Ryosuke Hamada ◽  
Shotaro Yamashita ◽  
Kazuyoshi Saida
Keyword(s):  
Phase Field ◽  
Stainless Steels ◽  
Field Method ◽  
Duplex Stainless Steels ◽  
Phase Field Method ◽  
Base Metals ◽  
Phase Dissolution

scholarly journals Viscoelastic phase-field fracture using the framework of representative crack elements

2021 ◽  
Author(s):  
Bo Yin ◽  
Johannes Storm ◽  
Michael Kaliske
Keyword(s):  
Phase Field ◽  
Consistency Condition ◽  
Field Method ◽  
Anisotropic Elasticity ◽  
Phase Field Method ◽  
Internal Variables ◽  
Crack Model ◽  
Material Degradation ◽  
Discrete Crack ◽  
Deformation State

AbstractThe promising phase-field method has been intensively studied for crack approximation in brittle materials. The realistic representation of material degradation at a fully evolved crack is still one of the main challenges. Several energy split formulations have been postulated to describe the crack evolution physically. A recent approach based on the concept of representative crack elements (RCE) in Storm et al. (The concept of representative crack elements (RCE) for phase-field fracture: anisotropic elasticity and thermo-elasticity. Int J Numer Methods Eng 121:779–805, 2020) introduces a variational framework to derive the kinematically consistent material degradation. The realistic material degradation is further tested using the self-consistency condition, which is particularly compared to a discrete crack model. This work extends the brittle RCE phase-field modeling towards rate-dependent fracture evolution in a viscoelastic continuum. The novelty of this paper is taking internal variables due to viscoelasticity into account to determine the crack deformation state. Meanwhile, a transient extension from Storm et al. (The concept of representative crack elements (RCE) for phase-field fracture: anisotropic elasticity and thermo-elasticity. Int J Numer Methods Eng 121:779–805, 2020) is also considered. The model is derived thermodynamic-consistently and implemented into the FE framework. Several representative numerical examples are investigated, and consequently, the according findings and potential perspectives are discussed to close this paper.

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