The Mechanical-Stress-Field of Matrix in Eutectic Ceramic Composite

2011 ◽  
Vol 121-126 ◽  
pp. 3607-3611
Author(s):  
Zhao Gang Cheng ◽  
Xin Hua Ni ◽  
Xie Quan Liu
Keyword(s):  
Stress Field ◽  
Mechanical Stress ◽  
Ceramic Composite ◽  
Composite Ceramic ◽  
Composite Ceramics ◽  
Eutectic Composite ◽  
Nano Fiber ◽  
The Matrix ◽  
Stress Boundary Condition ◽  
Stress Boundary

Based on the interaction between nano-fiber and eutectic interphase, forth-phase mode is used to get the mechanical stress field of matrix in eutectic composite ceramics. The effective flexibility increment tensor of eutectic ceramic composite is obtained by the volumetric average strain. The remote stress boundary condition of the eutectic composite ceramis is accounted for getting the mechanical stress field in matrix. The results show the mechanical stress field of the matrix is associated with the stiffness and the volume fractions of each component in eutectic composite ceramic , the shape of interphase and nano-fiber. The stresses in matrix will decrease due to the strong constraining effects of the eutectic interphase. The eutectic interphase make the eutectic composite ceramics strengthen.

Micro-Stress-Field of Lamellar Inclusion in Eutectic Composite Ceramic

2012 ◽  
Vol 204-208 ◽  
pp. 4433-4436 ◽  
Author(s):  
Xie Quan Liu ◽  
Xin Hua Ni ◽  
Jing Zhang ◽  
Xiang Feng Meng
Keyword(s):  
Stress Field ◽  
Composite Ceramic ◽  
Apparent Size ◽  
Phase Cell ◽  
Ceramic Analysis ◽  
Eutectic Composite ◽  
Three Phase ◽  
Stress Boundary Condition ◽  
Stress Boundary ◽  
Remote Stress

According to the interaction between lamellar inclusion and interphase, forth-phase model is suggested to determine the micro-stress-field distribution of three-phase cell in eutectic composite ceramic. On the basis of the volumetric average strain, the effective compliance tensor increment of eutectic composite ceramic is obtained. The remote stress boundary condition of the eutectic composite ceramic is accounted for getting the micro-stress-field of lamellar inclusion in eutectic composite ceramic. Analysis shows that the micro-stress-field of the lamellar inclusion in eutectic composite ceramic is associated with the stiffness and the volume fractions of each component in eutectic composite ceramic, the shape of interphase and lamellar inclusion. The-micro-stress field has apparent size effect: three direction stresses increase with the thickness of lamellar inclusion.

Elastic Constants of Eutectic Composite Ceramic Containing Parallel Lamellar Inclusion

2012 ◽  
Vol 251 ◽  
pp. 285-288
Author(s):  
Yun Wei Fu ◽  
Xie Quan Liu ◽  
Xin Hua Ni ◽  
Hong Na Cao
Keyword(s):  
Elastic Constant ◽  
Effective Stress ◽  
Elastic Constants ◽  
Transverse Isotropy ◽  
Analytical Formula ◽  
Composite Ceramic ◽  
Composite Ceramics ◽  
Eutectic Composite ◽  
Effective Elastic Constants ◽  
The Matrix

The eutectic composite ceramic is composed of parallel lamellar inclusions distributed in the matrix. First, the recessive expression for the effective stress and the flexibility increment tensor of eutectic composite ceramic are obtained according to the four-phase model. Second, the analytical formula which contains elastic constant is given by applying Taylor’s formula. The eutectic composite ceramic is transverse isotropy, so there are five elastic constants. Third, the effective elastic constants of composite ceramics are predicted.

Interaction between two nanoscale elliptical holes with surface tension

2018 ◽  
Vol 24 (5) ◽  
pp. 1556-1566 ◽  
Author(s):  
Shuang Wang ◽  
Cun-Fa Gao ◽  
Zeng-Tao Chen
Keyword(s):  
Surface Tension ◽  
Stress Field ◽  
Hoop Stress ◽  
Elliptical Hole ◽  
Integral Form ◽  
Maximum Hoop Stress ◽  
Stress Boundary Condition ◽  
Elliptical Holes ◽  
Basic Equations ◽  
Stress Boundary

In this paper, the plane problem of two elliptical nanoscale holes with surface tension is investigated. Firstly, the basic equations are given via the complex variable methods. Then, the stress boundary condition caused by surface tension is derived through the integral-form Gurtin–Murdoch model. The problem is finally solved by the conformal mapping along with the series expansion methods. The results show that the stress field decreases as the two holes become further away from each other. When the distance between the two holes is more than three times the sum of their sizes, the interaction between the two holes can be neglected. In addition, the stress field is greatly influenced by the orientation, aspect ratio and size of the holes. The positions of the maximum hoop stress are also discussed. When the two elliptical holes are put close horizontally, the hoop stress around one hole usually obtain its maximum at the endpoint close to the other hole. However, if one elliptical hole is not horizontal, the hoop stress around it will no longer attain its maximum at the endpoints. Another exception is that when one elliptical hole becomes larger, the hoop stress around the smaller hole would tend to achieve a local minimum at the endpoint close to the larger hole.

The intrinsic strength of triangular symmetrical composite eutectic

2015 ◽  
Vol 12 (6) ◽  
pp. 533-540
Author(s):  
Jinfeng Yu ◽  
Xiequan Liu ◽  
Xinhua Ni
Keyword(s):  
Covalent Bond ◽  
Composite Ceramic ◽  
Composite Ceramics ◽  
Eutectic Composite ◽  
Micro Structure ◽  
Macroscopic Structure ◽  
Pile Up ◽  
Distribution Of Stress ◽  
Intrinsic Strength ◽  
Structure Properties

Composite ceramic has the excellent properties at normal and high temperatures, especially when the structure of the composite eutectic is triangular symmetrical. Obviously, mechanical behavior and fracture properties of composite ceramic closely relates to the micro-structure of symmetrical triangular eutectic. In order to reveal the mechanical properties of eutectic composite ceramic, it is necessary to determine the intrinsic strength of triangular composite eutectic. Since the fiber and matrix of triangular symmetrical composite eutectic sharing a same covalent bond, the theoretical cohesion strength of symmetrical triangular eutectic was obtained by the combination-separation displacement of intrinsic bond. Basing on micro-structure plastic deformation before fracture of composite eutectic matrix, the dislocation pile-up model of eutectic composite ceramics was established. And then intrinsic bond fracture shear stress of triangular symmetrical composite eutectic was given by using the theory of dislocation pile-up. According to the macroscopic structure properties of triangular symmetrical composite eutectic and the distribution of stress field of composite eutectic, intrinsic strength of eutectic was obtained. The results shows that intrinsic strength of triangular symmetrical composite eutectic possessed clear size-dependence and the stress decreases with the increases of the diameter of fiber inclusions.

Screw Dislocations in a Three-Phase Composite Cylinder Model With Interface Stress

2008 ◽  
Vol 75 (4) ◽  
Author(s):  
Q. H. Fang ◽  
Y. W. Liu ◽  
P. H. Wen
Keyword(s):  
Boundary Condition ◽  
Classical Case ◽  
Interface Stress ◽  
Composite Cylinder ◽  
Screw Dislocations ◽  
Three Phase ◽  
Cylinder Model ◽  
The Matrix ◽  
Stress Boundary Condition ◽  
Stress Boundary

A three-phase composite cylinder model is utilized to study the interaction between screw dislocations and nanoscale inclusions. The stress boundary condition at the interface between nanoscale inclusion and the matrix is modified by incorporating surface/interface stress. The explicit solution to this problem is derived by means of the complex variable method. The explicit expressions of image forces exerted on screw dislocations are obtained. The mobility and the equilibrium positions of the dislocation near one of the inclusions are discussed. The results show that, compared to the classical solution (without interface stress), more equilibrium positions of the screw dislocation may be available when the dislocation is close to the nanoscale inclusion due to consider interface stress. Also, the mobility of the dislocation in the matrix will become more complex than the classical case.

Size Dependent Micro-Stress-Field of Fibers in Eutectic Ceramic Rod

2010 ◽  
Vol 168-170 ◽  
pp. 226-229
Author(s):  
Hai Xing Lu ◽  
Xie Quan Liu ◽  
Xin Hua Ni ◽  
Tao Sun ◽  
Bao Feng Li
Keyword(s):  
Stress Field ◽  
Local Stress ◽  
Apparent Size ◽  
Average Strain ◽  
Size Dependent ◽  
Three Phase ◽  
Stress Boundary Condition ◽  
Stress Boundary ◽  
Remote Stress ◽  
Local Stress Field

Considering the interaction between fiber-inclusion and strong constraining interphase, forth-phase model is suggested to determine the local stress field distribution of three-phase element in eutectic ceramic rod. On the basis of the volumetric average strain, the effective compliance tensor increment of eutectic ceramic rod is obtained. The remote stress boundary condition of the eutectic ceramic rod is accounted for getting the micro stress field of fibers in eutectic ceramic rod. The results show the micro stress field of the fiber-inclusion in eutectic ceramic rod is associated with the stiffness and the volume fractions of each component in eutectic ceramic rod, the shape of interphase and fiber. The micro stress field has apparent size effect: three direction stresses increase with the diameter of fiber- inclusion.

The Damage Finite Element Analysis of Eutectic Composite Ceramic Containing Lamellae

2011 ◽  
Vol 121-126 ◽  
pp. 473-477
Author(s):  
Shu Qin Zhang ◽  
Xin Hua Ni ◽  
Xie Quan Liu ◽  
Ying Chen Ma
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Field ◽  
Composite Ceramic ◽  
Element Model ◽  
Eutectic Composite ◽  
Element Analysis ◽  
Matrix Fracture ◽  
Damage Process ◽  
The Finite Element Model

According to microstructures in eutectic composite ceramic, the finite element model of composite with eutectic interphase is established. The mechanical stress field of eutectic composite ceramic containing lamellae is simulated. APDL programming in ANSYS is used to analyze the damage process of eutectic composite ceramic. Results show that the failure of eutectic composite ceramic is determined by the damage of matrix. As load is increasing, the damage will elongate along the interphase and extend to the internal of matrix. At last the damage arouses matrix fracture.

Toughening Analysis for Eutectic Composite Ceramic Containing Lamellae

2012 ◽  
Vol 204-208 ◽  
pp. 4071-4074
Author(s):  
Xin Hua Ni ◽  
Cheng Chen ◽  
Xie Quan Liu ◽  
Wan Heng He
Keyword(s):  
Residual Stress ◽  
Stress Field ◽  
Frictional Force ◽  
Composite Ceramic ◽  
Toughening Mechanism ◽  
Eutectic Composite ◽  
Residual Stress Field ◽  
Pull Out

On basis of the residual-stress-field of the composite ceramic, the frictional force on the boundary of the lamellae can be computed. Then the frictional work is determined. The pull-out toughening mechanism is gotten. The result shows that the toughening value is dependent on the size of lamellae: the pull-out toughening value will increase as the thickness of the lamellae increase.

Effective Elastic Constants of Fiber-Eutectics and Transformation Particles Composite Ceramic

2010 ◽  
Vol 177 ◽  
pp. 182-185 ◽  
Author(s):  
Bao Feng Li ◽  
Jian Zheng ◽  
Xin Hua Ni ◽  
Ying Chen Ma ◽  
Jing Zhang
Keyword(s):  
Elastic Modulus ◽  
Elastic Constant ◽  
Effective Stress ◽  
Elastic Constants ◽  
Transverse Isotropy ◽  
Analytical Formula ◽  
Composite Ceramic ◽  
Phase Model ◽  
Composite Ceramics ◽  
Effective Elastic Constants

The composite ceramics is composed of fiber-eutectics, transformation particles and matrix particles. First, the recessive expression between the effective stress in fiber-eutectic and the flexibility increment tensor is obtained according to the four-phase model. Second, the analytical formula which contains elastic constant of the fiber-eutectic is obtained applying Taylor’s formula. The eutectic is transverse isotropy, so there are five elastic constants. Third, the effective elastic constants of composite ceramics are predicted. The result shows that the elastic modulus of composite ceramic is reduced with the increase of fibers fraction and fibers diameter.

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