Collinear Crack Problem in Antiplane Elasticity for a Strip of Functionally Graded Materials

2004 ◽  
Vol 20 (3) ◽  
pp. 167-175 ◽  
Author(s):  
Y. Z. Chen
Keyword(s):  
Stress Intensity Factor ◽  
Integral Equation ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Crack Problem ◽  
Functionally Graded ◽  
Elementary Solution ◽  
Collinear Crack ◽  
Graded Materials ◽  
Antiplane Elasticity

AbstractIn this paper, elastic analysis for a collinear crack problem in antiplane elasticity of functionally graded materials (FGMs) is present. An elementary solution is obtained, which represents the traction applied at a point “x” on the real axis caused by a point dislocation placed at a point “t” on the same real axis. The Fourier transform method is used to derive the elementary solution. After using the obtained elementary solution, the singular integral equation is formulated for the collinear crack problem. Furthermore, from the solution of the singular integral equation the stress intensity factor at the crack tip can be evaluated immediately. In the solution of stress intensity factor, influence caused by the materials property “α” is addressed. Finally, numerical solutions are presented.

SINGULAR INTEGRAL EQUATION METHOD FOR A MOVING CRACK PROBLEM IN ANTIPLANE ELASTICITY OF FUNCTIONALLY GRADED MATERIALS

2007 ◽  
Vol 04 (03) ◽  
pp. 475-492 ◽  
Author(s):  
Y. Z. CHEN ◽  
X. Y. LIN
Keyword(s):  
Integral Equation ◽  
Singular Integral Equation ◽  
Functionally Graded Materials ◽  
Material Property ◽  
Singular Integral ◽  
Crack Problem ◽  
Functionally Graded ◽  
Moving Crack ◽  
Graded Materials ◽  
Antiplane Elasticity

In this paper, elastic analysis for a Yoffe moving crack problem in antiplane elasticity of the functionally graded materials (FGMs) is presented. The crack is assumed to move with a constant velocity V. The traction applied on the crack face is arbitrary. The Fourier transform method is used to derive an elementary solution. Furthermore, using the obtained elementary solution a singular integral equation for the problem is obtained. After the singular integral equation is solved, the stress intensity factor (SIF) can be evaluated immediately. In the case of evaluating the SIFs at the leading crack tip and the trailing crack tip, the difference between the two cases is investigated. From the numerical solution of the SIFs, the influence caused by the velocity V and the FGM material property β1 are addressed. It is found that when the FGM material property β1 = 0, i.e. the homogeneous case, the SIFs at the crack tips do not depend on the moving velocity of the crack. Finally, numerical examples are given.

Dynamic Analysis of Antiplane Crack under SH-Waves in the Functionally Graded Materials

2007 ◽  
Vol 353-358 ◽  
pp. 38-41
Author(s):  
Xin Gang Li ◽  
Cheng Jin ◽  
Li Zhang ◽  
Da Yong Chu
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Functionally Graded Materials ◽  
Dynamic Stress ◽  
Dynamic Stress Intensity Factor ◽  
Infinite Plate ◽  
Functionally Graded ◽  
Graded Materials ◽  
Sh Waves

In this paper, the behavior of a finite crack in an infinite plate of functionally graded materials (FGM) with free boundary subjected to SH-waves is considered. To make the analysis tractable, it is assumed that the material properties vary exponentially with the thickness direction and the problem is transformed into a dual integrated equation with the method of integral transform. The dynamic stress intensity factor is obtained using Schmidt method. The numerical examples are presented to demonstrate this numerical technique for SH-waves propagating in FGM plate. Finally the number of the waves, the gradient parameter of FGM and the angle of the incidence upon the dynamic stress intensity factor are also given.

scholarly journals Investigation on the Effect of Crack Length on Mechanical Properties of Functionally Graded Materials

2010 ◽  
Vol 44-47 ◽  
pp. 2244-2248
Author(s):  
Gang Chen ◽  
Xi Yu Zhao ◽  
Peng Cheng Zhai
Keyword(s):  
Mechanical Properties ◽  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Crack Length ◽  
Pure Metal ◽  
Functionally Graded ◽  
Crack Tip Field ◽  
Graded Materials ◽  
Barrier Coating

In this article, the thermo-mechanical responses of ceramic/metal functionally graded thermal barrier coating(TBC) in work environment are analyzed by a finite element method. Both the crack-tip field and the stress intensity factor of functionally graded TBC are analyzed and calculated. It is discussed that the effect of crack length on mechanical properties of functionally graded TBC in the condition creep and no creep of pure metal. The numerical results indicate that the effect of crack length(a/t) is negligible to temperature distributions and the maximum displacements of whole model but remarkable to the 1st principal stress and stress intensity factor of crack region. Moreover, creep phenomenon of pure metal can relax the value of displacement, stress and stress intensity factor but do not alter their distribution.

The Moving Crack Problem of Orthotropic Functionally Graded Materials under Antiplane Loading

2008 ◽  
Vol 33-37 ◽  
pp. 687-692
Author(s):  
Jun Lin Li ◽  
Zhong He Sui ◽  
Wei Yang Yang
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Functionally Graded Materials ◽  
Dynamic Stress ◽  
Dynamic Stress Intensity Factor ◽  
Functionally Graded ◽  
Infinite Strip ◽  
Graded Materials ◽  
Moving Speed

Dynamic problems of Yoffe mode crack are studied under antiplane shear impact in infinite orthotropic functionally graded materials. The shear modules in two directions are assumed to vary in terms with power function form of dual parameters of arbitrary time power. By using integral transform-dual integral equations method, the stress field and dynamic stress intensity factor near crack tip are obtained. And the influences of material in homogenous coefficient and graded parameters and crack moving speed to dynamic stress intensity factor are analyzed in virtue of Matlab software. Results show that the dimensionless dynamic stress intensity factor will decrease with the increase of moving speed of crack, which is opposite to the result of the dynamic problem of infinite strip in FGM. And the dimensionless dynamic stress intensity factor will decrease with the increase of graded parameters and rise with the increase of material in homogenous coefficient.

Fracture Dynamics of a Mode III Moving Crack Impacted by Elastic Wave in Functionally Graded Materials

2010 ◽  
Vol 105-106 ◽  
pp. 683-686
Author(s):  
Xin Gang Li ◽  
Zhen Qing Wang ◽  
Nian Chun Lü
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Functionally Graded Materials ◽  
Dynamic Stress ◽  
Dynamic Stress Intensity Factor ◽  
Functionally Graded ◽  
Moving Crack ◽  
Graded Materials ◽  
Sh Waves

The dynamic stress field under the SH-waves at the moving crack tip of functionally graded materials is analyzed, and the influences of parameters such as graded parameter, crack velocity, the angle of the incidence and the number of the waves on dynamic stress intensity factor are also studied. Due to the same time factor of scattering wave and incident wave, the scattering model of the crack tip can be constructed by making use of the displacement function of harmonic load in the infinite plane. The dual integral equation of moving crack problem subjected to SH-waves is obtained through Fourier transform with the help of the exponent model of the shear modulus and density, then have some process on the even and odd term of the integral kernel. The displacement is expanded into series form using Jacobi Polynomial, and then the semi-analytic and numerical solutions of dynamic stress intensity factor are derived with Schmidt method.

Edge Crack in an Elastic Strip on a Liquid Foundation

1989 ◽  
Vol 33 (03) ◽  
pp. 214-220
Author(s):  
Paul C. Xirouchakis ◽  
George N. Makrakis
Keyword(s):  
Stress Intensity Factor ◽  
Integral Equation ◽  
Fourier Transform ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Edge Crack ◽  
Applied Pressure ◽  
Theory Of Elasticity ◽  
Elastic Strip ◽  
Pressure Loading

The behavior of a long elastic strip with an edge crack resting on a liquid foundation is investigated. The faces of the crack are opened by an applied pressure loading. The deformation of the strip is considered within the framework of the linear theory of elasticity assuming plane-stress conditions. Fourier transform techniques are employed to obtain integral expressions for the stresses and displacements. The boundary-value problem is reduced to the solution of a Fredholm integral equation of the second kind. For the particular case of linear pressure loading, the stress-intensity factor is calculated and its dependence is shown on the depth of the crack relative to the thickness of the strip. Application of the present results to the problem of flexure of floating ice strips is discussed.

Sign in / Sign up

Export Citation Format

Share Document