STUDY ON THE FRACTURE BEHAVIOR OF W-NI-FE HEAVY ALLOYS

The fracture behaviors of tungsten alloys 91 W -6.3 Ni -2.7 Fe were investigated by tensile tests and numerical simulations. Firstly, tensile tests were conducted on the S-570 SEM with an in-situ tensile stage. With this system, the process of deformation, damage and evolution in micro-area can be tracked and recorded, and at the same time, the load-strain curve can be drawn. Secondly, the 2D finite element model of a unit cell for the tungsten alloys was established by using finite element program. By copying the unit cell model, the macro-model of the alloys was given. Dozen of cases were performed to simulate the fracture behaviors of tungsten alloys. Thirdly, the random model of the alloys was established. The fracture patterns of the alloys were investigated by the model. The interface between the tungsten particle and the matrix was explored in details. The effect of interface strength on the fracture patterns of the alloys was taken into account. A good agreement was achieved between the experimental results and the numerical predictions.

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Thermo-Viscoelastic Response of 3D Braided Composites Based on a Novel FsMsFE Method

Materials ◽

10.3390/ma14020271 ◽

2021 ◽

Vol 14 (2) ◽

pp. 271

Author(s):

Jun-Jun Zhai ◽

Xiang-Xia Kong ◽

Lu-Chen Wang

Keyword(s):

Finite Element ◽

Cell Model ◽

Structural Parameters ◽

Thermal Relaxation ◽

Viscoelastic Behavior ◽

Unit Cell ◽

Time Dependent ◽

3D Braided Composites ◽

Equivalent Time ◽

Representative Unit Cell

A homogenization-based five-step multi-scale finite element (FsMsFE) simulation framework is developed to describe the time-temperature-dependent viscoelastic behavior of 3D braided four-directional composites. The current analysis was performed via three-scale finite element models, the fiber/matrix (microscopic) representative unit cell (RUC) model, the yarn/matrix (mesoscopic) representative unit cell model, and the macroscopic solid model with homogeneous property. Coupling the time-temperature equivalence principle, multi-phase finite element approach, Laplace transformation and Prony series fitting technology, the character of the stress relaxation behaviors at three scales subject to variation in temperature is investigated, and the equivalent time-dependent thermal expansion coefficients (TTEC), the equivalent time-dependent thermal relaxation modulus (TTRM) under micro-scale and meso-scale were predicted. Furthermore, the impacts of temperature, structural parameters and relaxation time on the time-dependent thermo-viscoelastic properties of 3D braided four-directional composites were studied.

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Finite Element Analysis on the Unloading Elastic Modulus of Aluminum Foams by Unit-cell Model

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/288/1/012069 ◽

2018 ◽

Vol 288 ◽

pp. 012069 ◽

Cited By ~ 2

Author(s):

F Triawan ◽

B A Budiman ◽

F B Juangsa ◽

L A Prananto ◽

M Aziz

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Elastic Modulus ◽

Cell Model ◽

Unit Cell ◽

Unit Cell Model ◽

Aluminum Foams ◽

Element Analysis

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TENSILE PROPERTY AND CRACK PROPAGATION BEHAVIOR OF TUNGSTEN ALLOYS

International Journal of Modern Physics B ◽

10.1142/s0217979211100114 ◽

2011 ◽

Vol 25 (11) ◽

pp. 1475-1492 ◽

Cited By ~ 2

Author(s):

WEIDONG SONG ◽

HAIYAN LIU ◽

JIANGUO NING

Keyword(s):

Fixed Point ◽

Iteration Method ◽

Experimental System ◽

Unit Cell ◽

Cell Models ◽

Fixed Point Iteration ◽

Tungsten Alloys ◽

Propagation Behavior ◽

Numerical Predictions ◽

Microstructure Parameters

In situ SEM experimental system is employed to investigate the mechanical characteristics and the fracture behavior of 91W–6.3Ni–2.7Fe tungsten alloys. The crack initiation and propagation of tungsten alloys under tensile loadings are examined. Multi-particle unit cell models containing the microstructure characteristics of tungsten alloys are established. Fixed-point iteration method is firstly used for the multi-particle unit cell's boundary condition. By adopting the method, real displacement constrained conditions are applied on the multi-particle unit cell models. The mechanical and fracture behaviors of tungsten alloys under tensile loading are simulated. The effects of tungsten content, particle shape, particle size, and interface strength on the mechanical properties of tungsten alloys are analyzed. The relationship between the mechanical behaviors and the microstructure parameters is studied. A good agreement is obtained between the experimental results and the numerical predictions, verifying the rationality of the FE models using the fixed-point iteration method.

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Effect of Compressive and Shear Deformation of 2.5D Preform on its Stiffness of Composites

Materials Science Forum ◽

10.4028/www.scientific.net/msf.943.75 ◽

2019 ◽

Vol 943 ◽

pp. 75-80

Author(s):

Fang Bin Lin ◽

Ying Dai ◽

Han Yang Li ◽

Yang Qu ◽

Wen Xiao Li

Keyword(s):

Finite Element ◽

Shear Deformation ◽

Cell Model ◽

Deformation Mode ◽

Element Model ◽

Tensile Tests ◽

Woven Composites ◽

Forming Process ◽

Element Analysis ◽

Plane Shear

Transverse compaction and in-plane shear deformartion are the dominative deformation mode for woven preform during forming process. A full finite element model of the 2.5D woven composites has been established by the computed tomography (CT) in this paper. Based on the energy method, the effective orthotropic/anisotropic stiffness coefficientsCijare calculated by performing a finite element analysis (FEA) of this full cell model. Using this model, the effects of the compaction and shear deformation of the 2.5D woven preform on the composites stiffness are investigated in detail. Compared the results of the static tensile tests, the rationality of the model and the method is verified.

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On the Effect of Unit-Cell Parameters in Predicting the Elastic Response of Wood-Plastic Composites

Journal of Engineering ◽

10.1155/2013/456398 ◽

2013 ◽

Vol 2013 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Fatemeh Alavi ◽

Amir Hossein Behravesh ◽

Abbas S. Milani ◽

Davoud Karimi

Keyword(s):

Finite Element ◽

Modulus Of Elasticity ◽

Strain Curve ◽

Unit Cell ◽

Elastic Response ◽

Geometrical Parameters ◽

Uniaxial Test ◽

Cell Parameters ◽

Plastic Composite ◽

The Difference

This paper presents a study on the effect of unit-cell geometrical parameters in predicting elastic properties of a typical wood plastic composite (WPC). The ultimate goal was obtaining the optimal values of representative volume element (RVE) parameters to accurately predict the mechanical behavior of the WPC. For each unit cell, defined by a given combination of the above geometrical parameters, finite element simulation in ABAQUS was carried out, and the corresponding stress-strain curve was obtained. A uniaxial test according to ASTM D638-02a type V was performed on the composite specimen. Modulus of elasticity was determined using hyperbolic tangent function, and the results were compared to the sets of finite element analyses. Main effects of RVE parameters and their interactions were demonstrated and discussed, specially regarding the inclusion of two adjacent wood particles within one unit cell of the material. Regression analysis was performed to mathematically model the RVE parameter effects and their interactions over the modulus of elasticity response. The model was finally employed in an optimization analysis to arrive at an optimal set of RVE parameters that minimizes the difference between the predicted and experimental moduli of elasticity.

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Theoretical aspects of selecting repeated unit cell model in micromechanical analysis using displacement-based finite element method

Chinese Journal of Aeronautics ◽

10.1016/j.cja.2017.05.010 ◽

2017 ◽

Vol 30 (4) ◽

pp. 1417-1426 ◽

Cited By ~ 4

Author(s):

Lijun GAO ◽

Chengyu WANG ◽

Zhanli LIU ◽

Zhuo ZHUANG

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Cell Model ◽

Unit Cell ◽

Unit Cell Model ◽

Micromechanical Analysis ◽

Repeated Unit ◽

Displacement Based ◽

Element Method

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Comparative Study of Predictive Finite Element Methods for Mechanical Properties in 2D Woven Carbon/Carbon Composites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.59.116 ◽

2008 ◽

Vol 59 ◽

pp. 116-119

Author(s):

Joshim Ali ◽

Derek Buckthorpe ◽

Allister Cheyne ◽

Johar Farooqi ◽

Paul M. Mummery

Keyword(s):

Finite Element ◽

Three Dimensional ◽

Tensile Tests ◽

Unit Cell ◽

Carbon Composites ◽

Fe Model ◽

Dimensional Finite Element ◽

Composite Microstructure ◽

Tomographic Data ◽

Three Dimensional Finite Element

Three-dimensional finite element (FE) methods are used to predict the Young’s modulus of two types of 2D woven carbon/carbon composites. Tensile tests are performed to validate the predictions. The results indicate that a novel image-based route in generating FE meshes gave strong agreement with experimental data, while a comparative unit cell FE model of the structure was found to be poorer. The differences between the image-based and unit cell methodologies were the consideration of the finer architectures of the composites and their porosity. The image-based approach highlighted true porosity in the structure due to meshes forming directly from X-ray tomographic data. However, the finer fibre architectures of the composites were compromised because of limitations in the pixel resolutions employed during the initial scanning process. In comparison, the unit cell models were based solely on idealisations of the composite microstructure, in which porosity was neglected.

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Dynamic Behavior of Tungsten Alloys

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.33-37.449 ◽

2008 ◽

Vol 33-37 ◽

pp. 449-454 ◽

Cited By ~ 1

Author(s):

Wei Dong Song ◽

Hai Yan Liu ◽

Hui Lan Ren

Keyword(s):

Mechanical Properties ◽

Finite Element ◽

Dynamic Behavior ◽

Three Dimensional ◽

Element Model ◽

Tungsten Alloy ◽

Lagrangian Analysis ◽

Tungsten Alloys ◽

Numerical Predictions ◽

Alloy Target

The plate impact experiments have been conducted to investigate the dynamic behavior of 91W-6.3Ni-2.7Fe. Lagrangian analysis technique was introduced to discuss the mechanical properties of the tungsten alloys under high strain rate and the stress-strain curves of the tungsten alloys were given. Based on the experimental observations, the three-dimensional finite element models of projectile and tungsten alloy target are established by adopting ANSYS/LS-DYNA, Dozens of cases were performed to investigate the dynamic mechanical behavior of tungsten alloy target under impact loading. A good agreement between numerical predictions and experimental results was obtained, which suggests that the finite element model is efficient and credible to simulate the mechanical properties of tungsten alloys.

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Fracture Behavior of Particle Reinforced Metal Matrix Composites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.79-82.1487 ◽

2009 ◽

Vol 79-82 ◽

pp. 1487-1490

Author(s):

Wei Dong Song ◽

Hai Yan Liu ◽

Jian Guo Ning

Keyword(s):

Fixed Point ◽

Metal Matrix Composites ◽

Iteration Method ◽

Metal Matrix ◽

Fracture Behavior ◽

Unit Cell ◽

Matrix Composites ◽

Fixed Point Iteration ◽

Tungsten Alloys ◽

Numerical Predictions

SEM experimental system was employed to investigate the fracture behavior of particle reinforced metal matrix composites (91%wt tungsten alloys) by in-situ experiments. The fracture patterns of tungsten alloys under tensile loading were examined. Multi-particle unit cell models containing some important microstructure characteristics of tungsten alloys were established. By using fixed point iteration method, the displacement constraint conditions were applied on the multi-particle unit cell and the mechanical properties of tungsten alloys under tensile loadings were simulated. Comparison of the experimental results and the numerical predictions shows a good agreement between them, verifying the rationality of the FE models using the fixed point iteration method.

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