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Baolin Wang - One of the best experts on this subject based on the ideXlab platform.

  • Two-dimensional problem of thermoelectric materials with an Elliptic Hole or a rigid inclusion
    International Journal of Thermal Sciences, 2017
    Co-Authors: Aibing Zhang, Baolin Wang
    Abstract:

    Abstract The two-dimensional problems of an Elliptic Hole or a rigid inclusion embedded in a thermoelectric material subjected to uniform electric current density and energy flux at infinity are studied based on the complex variable method of Muskhelishvili and conformal mapping technique. The closed-form solutions of electric potential, temperature and stress components are presented according to electrical insulated and thermal exact boundary conditions on the rim of the Hole or inclusion. Numerical results are carried out to illustrate the influence of the value of major to minor axis ratio of the Elliptic geometry and heat conductivity of inhomogeneity on thermoelectric and stress fields. It is found that energy flux at surfaces of the Hole or rigid inclusion does not vanish due to the Joule heat and Seebeck effect when the electric field is applied. In addition, stress induced by applied electric field has a non-linear relationship with the electric current density. The heat conductivity of the air inside the Elliptic Hole reduces the concentration factors of energy flux and stress. However, the concentration factors of energy flux and stress at the bonding interface increase with the increasing values of heat conductivity of the flat rigid inclusion.

  • Thermoelectric fields and associated thermal stresses for an inclined Elliptic Hole in thermoelectric materials
    International Journal of Engineering Science, 2017
    Co-Authors: P. Wang, Baolin Wang
    Abstract:

    Abstract A theoretical model for the thermoelectric coupling analysis of thermal materials with an inclined Elliptic Hole is constructed. The extended problem of an Elliptic Hole under biaxial loading is also discussed. Theoretical and numerical results for the thermoelectric coupling resulting thermal stress are obtained. Results show that, for the biaxial loaded Elliptic Hole, the solution cannot be the linear superposition of the solutions of two uniaxial loaded cases due to the nonlinear coupling. For inclined Elliptic Hole, the maximum thermoelectric concentration occurs when the major axis is perpendicular to the loading direction. However, the maximum stress concentration occurs when the major axis is parallel to the loading direction. The solution of a circle Hole problem is given as a special case in the framework of Elliptic Hole problem. The crack problem is also discussed when the ellipse degenerates into a crack. It is found that all field intensity factors exhibit the traditional inverse square-root singularity at the crack tip. The mode I stress intensity factor only depends on the applied electric current. The mode II stress intensity factor only depends on the applied energy flux when the crack line is perpendicular to the loading direction. However, in the biaxial loading case, the mode II stress intensity factor relies on the applied electric current density and energy flux. This is the first paper to conduct a strict closed-form solution for an inclined Elliptic Hole in thermoelectric materials.

  • Explicit solutions of an Elliptic Hole or a crack problem in thermoelectric materials
    Engineering Fracture Mechanics, 2016
    Co-Authors: Aibing Zhang, Baolin Wang
    Abstract:

    Abstract The generalized two-dimensional problem of an Elliptic Hole or a crack in a thermoelectric material subjected to uniform electric current density and energy flux at infinity is investigated based on the complex variable method and the conformal mapping technique. Firstly, the exact solutions of electric potential, temperature and stress fields are presented with the assumption that the surfaces of the Elliptic Hole are electrically and thermally insulated. It is shown that both the concentration factors of electric current density and stress at Hole rim increase as the value of major to minor axis ratio of the Elliptic Hole increases. Then, explicit solutions are also obtained in closed-form when the Elliptic Hole degenerates into a crack. It is found that all fields exhibit an inverse square-root singularity at the crack tip, and electric current density and stress intensity factors are defined according to the traditional way. The results show that the mode-I and mode-II stress intensity factors are dependent on the applied electric current density and energy flux, respectively. Furthermore, the mode-I stress intensity factor induced by Joule heating effect has a non-linear relationship with the remote electric loads.

Cun-fa Gao - One of the best experts on this subject based on the ideXlab platform.

  • Electro-elastic fields in an Elliptic piezoelectric plane with an Elliptic Hole or a crack of arbitrary location
    Meccanica, 2017
    Co-Authors: Cun-fa Gao
    Abstract:

    Electro-elastic fields in an Elliptic piezoelectric plane with an Elliptic Hole or a crack of arbitrary location are studied based on the complex variable method and the assumption that the Elliptic Hole or the crack is impermeable to an electric field. The novel feature of the present work is to construct the complex potentials in a finite piezoelectric body with Faber series containing unknown coefficients. Using the given boundary conditions, the coefficients can be solved, and then the electro-elastic fields in the plane can be calculated. Finally, numerical examples are given for the electro-elastic fields in the plane and the electro-elastic intensity factors at the crack tips when the Hole degenerates into a crack. It is found that the sizes of the Elliptic plane and the Elliptic Hole (or the crack) have a great influence on electro-elastic fields (or the intensity factors of the crack).

  • solution of an orthotropic Elliptic plate with an Elliptic Hole or crack
    Symposium on Piezoelectricity Acoustic Waves and Device Applications, 2016
    Co-Authors: Hai-bing Yang, Ming Dai, Cun-fa Gao
    Abstract:

    Based on the complex variable method, the problem of an Elliptic plate with an Elliptic Hole or a crack is addressed under uniform tension or pressure imposed on the boundary of the Hole and on the edge of the plate. A series solution for the stress field inside the plate is derived using conformal mapping techniques, Faber series and Fourier expansion method. The stress fields around the Hole or crack relative to the distance between the Hole or crack and the edge of the plate are discussed in several examples. It is found that the hoop stress around the Hole and the stress intensity factors at the crack tips increase steeply with deceasing distance between the Hole or crack and the edge of the plate.

  • two dimensional problems in a soft ferromagnetic solid with an Elliptic Hole or a crack
    International Journal of Engineering Science, 2012
    Co-Authors: Chao Chang, Cun-fa Gao, Yan Shi
    Abstract:

    Abstract This paper deals with the problem of an Elliptic Hole or a crack in a soft ferromagnetic solid under the magnetic field at infinity. First, based on the simplified versions of the linear theory of Pao and Yeh (1973) , the general solution of an Elliptical Hole is obtained according to exact boundary conditions at the rim of the Hole. Then, when the Hole degenerates into a crack, explicit solutions are given for potential functions and intensity factors of total stresses. In the above analysis, three kinds of magnetic boundary conditions, that is, magnetically permeable, impermeable and conducting boundary condition, are considered on the surface of the Hole or the crack, respectively. It is found that in general, the total stresses always have the classical singularity of the r - 1 / 2 -type at the crack tips for considered three crack models, and that the applied magnetic field may either enhance or retard crack growth depending on the magnetic boundary conditions adopted on the crack faces, and the Maxwell stresses on the crack faces and at infinity. Since the present solutions for a crack are given in explicit form, they can also serve as a benchmark to test the validity of various analysis approaches or assumptions to more complicated crack problems in a soft ferromagnetic solid.

  • study on bending problems of piezoelectric laminated plates with an Elliptic Hole
    Symposium on Piezoelectricity Acoustic Waves and Device Applications, 2010
    Co-Authors: Jian Qiu, Cun-fa Gao, Xianghua Dai
    Abstract:

    Based on the Lekhniskii's complex-variable-method, the bending problems of an infinite piezoelectric laminated plate containing an Elliptic Hole are investigated in this paper. The stress potentials, deflection and electric potentials are firstly derived for the plate which is subjected to uniform bending moments at infinity. Then, the solutions of the bending moments, electric displacement and membrane stress are obtained, respectively. In addition, numerical results for the stress distribution and electric potential around the circular Hole are also presented.

  • an exact and explicit treatment of an Elliptic Hole problem in thermopiezoelectric media
    International Journal of Solids and Structures, 2002
    Co-Authors: Cun-fa Gao, Yingtao Zhao, Minzhong Wang
    Abstract:

    Abstract This paper presents an exact solution for the problem of an Elliptic Hole or a crack in a thermopiezoelectric solid. First, based on the extended version of Eshelby–Stroh's formulation, the generalized 2D problems of an Elliptical Hole in a thermopiezoelectric medium subject to uniform heat flow and mechanical–electrical loads at infinity are studied according to exact boundary conditions at the rim of the Hole. The complex potentials in the medium and the electric field inside the Hole are obtained in closed form, respectively. Then, when the Hole degenerates into a crack, the explicit solutions for the field intensity factors near the crack tip and the electric field inside the crack are presented. It is shown that the singularities of all the field are dependent on the material constants, the applied heat load and mechanical loads at infinity, but not on the applied electric loads. It is also found that the electric field inside the crack is linearly variable, which is different from the result based on the impermeable crack model.

Jian-jun Han - One of the best experts on this subject based on the ideXlab platform.

  • Green's function for infinite thin plate with Elliptic Hole under bending heat source and interaction between Elliptic Hole and crack under uniform bending heat flux
    Journal of Thermal Stresses, 2016
    Co-Authors: Norio Hasebe, Jian-jun Han
    Abstract:

    ABSTRACTGreen's function is derived for the bending problem of an infinite thin plate with an Elliptic Hole under a bending heat source. Then the interaction problem between an Elliptic Hole and a crack in a thin plate under uniform bending heat flux is analyzed. First, the complex variable method is developed for the thermoelastic problem of bending. Then an exact solution in explicit form is derived for the Green's function by using the complex variable method. Distributions of temperature moment, heat flux moments, bending moments along the Hole edge are shown in figures. For solving the interaction problem, a solution for an infinite thin plate with an adiabatic Elliptic Hole under uniform bending heat flux, and two Green's functions of the plate under a bending heat source couple and a bending dislocation are given. The interaction problem then reduces into singular integral equations using the Green's functions and the principle of superposition. After the equations are solved numerically, the momen...

  • A hybrid-Trefftz element containing an Elliptic Hole
    Finite Elements in Analysis and Design, 2006
    Co-Authors: Manicka Dhanasekar, Jian-jun Han, Qing-hua Qin
    Abstract:

    Much work on special elements that simplify geometrical modelling of structures containing Holes, cracks and/ or inclusions has been reported extensively in the literature. This paper presents a hybrid-Trefftz element containing Elliptic Hole formulated using Hellinger-Reissner principle by employing trial functions based on the mapping technique and the Cauchy integral method. The element presented in this paper could be regarded as an improved formulation over Piltner [Special finite elements with Holes and internal cracks, Int. J. Numer. Methods Eng 21 (1985) 1471-1485] element because the chosen trail functions in this paper have provided relatively more stable solutions. The use of the element with other ordinary displacement-based finite elements has also yielded very accurate solutions even when very coarse meshes relative to the size of the Elliptic Hole have been used.

  • green s function for a thermomechanical mixed boundary value problem of an infinite plane with an Elliptic Hole
    Journal of Thermal Stresses, 2001
    Co-Authors: Jian-jun Han, Norio Hasebe
    Abstract:

    This article derives the Green's function for a thermomechanical mixed boundary value problem of an infinite plane with an Elliptic Hole under a pair of heat source and sink. To derive the Green's function in closed form, the Cauchy integral method and a basic Green's function for an external force boundary value problem with a pair of heat source and sink are employed. Illustrative numerical results for temperature, heat flux, and stress along the Hole edge and stress intensity factors when the Hole collapses into a crack are presented graphically.

Norio Hasebe - One of the best experts on this subject based on the ideXlab platform.

  • Green's function for infinite thin plate with Elliptic Hole under bending heat source and interaction between Elliptic Hole and crack under uniform bending heat flux
    Journal of Thermal Stresses, 2016
    Co-Authors: Norio Hasebe, Jian-jun Han
    Abstract:

    ABSTRACTGreen's function is derived for the bending problem of an infinite thin plate with an Elliptic Hole under a bending heat source. Then the interaction problem between an Elliptic Hole and a crack in a thin plate under uniform bending heat flux is analyzed. First, the complex variable method is developed for the thermoelastic problem of bending. Then an exact solution in explicit form is derived for the Green's function by using the complex variable method. Distributions of temperature moment, heat flux moments, bending moments along the Hole edge are shown in figures. For solving the interaction problem, a solution for an infinite thin plate with an adiabatic Elliptic Hole under uniform bending heat flux, and two Green's functions of the plate under a bending heat source couple and a bending dislocation are given. The interaction problem then reduces into singular integral equations using the Green's functions and the principle of superposition. After the equations are solved numerically, the momen...

  • A Comparative Study of Modeling the Magnetostatic Field in a Current-Carrying Plate Containing an Elliptic Hole
    IEEE Transactions on Magnetics, 2009
    Co-Authors: Norio Hasebe, Leon M. Keer, Qian Jane Wang
    Abstract:

    The presence of crack-like defects can cause an uneven distribution of the electric current density in a cracked conductor. To investigate the perturbation of the magnetic field resulting from the disturbed electric current, computational modeling of the magnetostatics is attempted on an infinite conductive plate, which contains an Elliptic Hole and is subjected to uniform current flow at infinity. Both 2-D and 3-D analyses are considered in this study. The 2-D analysis requires certain crucial assumptions and the governing Maxwell's equations are solved analytically in Elliptic coordinates. The 3-D numerical computation is based on superposition of the elementary solution, whose derivation utilizes the Biot-Savart law. To improve the efficiency of the 3-D calculation, an adaptive mesh refinement algorithm is implemented in the numerical discretization. Finally, through a comparative study, the validity of the introduced simplifications in the 2-D analysis is benchmarked with the 3-D computational results. The present study shows that the 2-D solution predicts the upper bound for the out-of-plane component of the magnetic field perturbed by the Elliptical Hole, whose semi-major axis does not exceed ten times the thickness of the plate.

  • interaction between a cracked Elliptic Hole and a line crack under uniform heat flux
    Transactions of the Japan Society of Mechanical Engineers. A, 2004
    Co-Authors: Takahiro Saito, Norio Hasebe, Xianfeng Wang
    Abstract:

    In this study the thermo-elastic analysis of a line crack interacting with a cracked Elliptic Hole and subjected to a uniform heat flux is carried out. By applying the complex variable method and rational mapping function technique, the solution to the given problem is obtained. This is accomplished by dividing the problem into the following three basic problems : (a) the problem of a cracked Elliptic Hole subjected to uniform heat flux (b) the problem of a cracked Elliptic Hole subjected to a heat source couple (c) and the problem of a cracked Elliptic Hole subjected to a point dislocation. By superposing the three basic problems so that the boundary condition of heat flux and stress on a line crack are satisfied, the solution to the given problem is obtained. Stress intensity factors at the crack tips are obtained soluting integral equation numerically and plotted for various orientation of the line crack and heat flux.

  • green s function for a thermomechanical mixed boundary value problem of an infinite plane with an Elliptic Hole
    Journal of Thermal Stresses, 2001
    Co-Authors: Jian-jun Han, Norio Hasebe
    Abstract:

    This article derives the Green's function for a thermomechanical mixed boundary value problem of an infinite plane with an Elliptic Hole under a pair of heat source and sink. To derive the Green's function in closed form, the Cauchy integral method and a basic Green's function for an external force boundary value problem with a pair of heat source and sink are employed. Illustrative numerical results for temperature, heat flux, and stress along the Hole edge and stress intensity factors when the Hole collapses into a crack are presented graphically.

Sham-tsong Shiue - One of the best experts on this subject based on the ideXlab platform.

  • Elastic interaction between screw dislocations and a microcrack near an Elliptic Hole
    Materials Chemistry and Physics, 1997
    Co-Authors: Sham-tsong Shiue
    Abstract:

    The elastic interaction between a screw dislocation and a microcrack near an Elliptic Hole was investigated. The stress field, the stress intensity factors at both tips of the microcrack, and the image force on the lattice dislocation were derived. The stress intensity factors at the crack tip and the image force on the lattice dislocation were both strongly affected by the Elliptic Hole, and were dependent on the positions of the lattice screw dislocation, the dislocations existing in the microcrack and Elliptic Hole, and the geometry of the Elliptic Hole. If a lattice dislocation arose from the right-hand-side tip of the microcrack by a mode III applied stress, the lattice dislocation had a shielding effect on the propagation of the right-hand-side crack tip, but had an enhancing effect on the movement of the left-hand-side crack tip. It was also found that the dislocations existing in the Elliptic Hole and microcrack played an important role on the fracture.

  • The Effect of an Elliptic Hole on the Elastic Interaction between Screw Dislocations and a Macrocrack
    physica status solidi (b), 1994
    Co-Authors: Sham-tsong Shiue
    Abstract:

    The effect of an Elliptic Hole on the elastic interaction between a screw dislocation and a macrocrack is investigated by the conformal mapping technique. The stress field, the stress intensity factor at the crack tip, and the force on the dislocation are derived. Both the stress intensity factor at the crack tip and the force on the dislocation are strongly influenced by the Elliptic Hole, and are dependent on the positions of the lattice screw dislocation, the dislocations in the Elliptic Hole, and the geometry of the Elliptic Hole. If the lattice dislocation arises from the macrocrack or infinity, the lattice dislocation always has a shielding effect on the propagation of the crack. It is also found that an Elliptic Hole with a smaller minor semi-axis b will induce a larger magnitude of the negative stress intensity factor at the crack tip, so it has a larger shielding effect on the crack propagation. Finally, several special cases of the results are also discussed.