摘要:

The explicit full-domain solutions for the thermoelastic problem of bonded dissimilar materials with a circular-arc anticrack have been obtained by applying the Hilbert problem formulation and a special technique of analytical continuation. It is noted that the singularities of the stress field near the arc anticrack tip are similar to those for the corresponding crack problem that would not be affected by the discontinuous jumps of the thermal properties across the interface. Both the rotation angle of an arc anticrack and stress intensity factors due to the application of remote heat flux are obtained in an explicit form. For the purpose of illustration, two typical examples for commonly used fiber-reinforced composites such as boron epoxy and glass epoxy system associated with an interface circular-arc anticrack are examined and detailed results are provided in graphical form. The situations under which kinked cracks will initiate from an arc anticrack tip are also discussed.

ISSN:0149-5739    

DOI:10.1080/014957399280689

出版商:Informa UK Ltd    

年代:1999

数据来源: Taylor

摘要:

The main objective of this study is to determine the stress intensity factors associated with a circumferential crack in a thin-walled cylinder subjected to quasi-static thermal loading. The cylinder is assumed to be a functionally graded material. In order to make the problem analytically tractable, the thin-walled cylinder is modeled as a layer on an elastic foundation whose thermal and mechanical properties are exponential functions of the thickness coordinate. Hence a plane strain crack problem is obtained. First temperature and thermal stress distributions for a crack-free layer are determined. Then using these solutions, the crack problem is reduced to a local perturbation problem where the only nonzero loads are the crack surface tractions. Both internal and edge cracks are considered. Stress intensity factors are computed as functions of crack geometry, material properties, and time.

ISSN:0149-5739    

DOI:10.1080/014957399280698

出版商:Informa UK Ltd    

年代:1999

数据来源: Taylor

摘要:

A method of analytical development of three-dimensional thermoelastic problems for a medium with nonhomogeneous material properties is developed in this article. Assuming that the shear modulus elasticity G, the thermal conductivity lambda, and the coefficient of linear thermal expansion alpha vary with the power product form of axial coordinate variable z and introducing two kinds of displacement functions and the thermoelastic displacement function, the system of fundamental differential equations for such a three-dimensional field is established. As an illustrative example, we consider the thermoelastic problem of a semi-infinite body. The three-dimensional temperature solution in a steady state is obtained and the associated components of thermal displacement and stress are evaluated theoretically. Numerical calculations are carried out for several cases taking into account the variety of the nonhomogeneous material properties of G, lambda, and alpha, and these results are shown graphically.

ISSN:0149-5739    

DOI:10.1080/014957399280706

出版商:Informa UK Ltd    

年代:1999

数据来源: Taylor

摘要:

Effective thermal conductivity of sintered spherical particles is estimated by a computer simulation. The simulation consists of (i)simulated random packing of equal spheres by a method of "rigid sphere free fall into a virtual box," (ii) finite element method (FEM) estimation of the thermal resistance of a "sintered" pair of spheres, and (iii) simulated heat conduction tests of a "random network," as a model of sintered particles, of thermal resistors with the estimated resistance; these tests yield the effective conductivity of sintered spherical particle aggregates. Statistical structures of the random packings of spheres are examined. The random packings constructed are standard "loose random packings." The cumulative diameter distribution of circles appearing on cross-sections of the packings is in complete agreement with the theoretical prediction for all three orthogonal directions, implying that the packing structures are isotropic. And, despite this result, the zenithal distribution of branch orientations deviates from a uniform one; more spheres are in contact with their neighbors at the zenithal angles of theta approxequal 45 degrees. The effective conductivities obtained are not isotropic but transversely isotropic, which is due to the deviation of branch orientations.

ISSN:0149-5739    

DOI:10.1080/014957399280715

出版商:Informa UK Ltd    

年代:1999

数据来源: Taylor

ISSN:0149-5739    

DOI:10.1080/014957399280724

出版商:Informa UK Ltd    

年代:1999

数据来源: Taylor