摘要:

This article is concerned with the problem of thermoelastic equilibrium of cylinders with microstructure under action of a temperature variation that is a polynomial in the axial coordinate. The cylinder is occupied by different thermoelastic materials.

ISSN:0149-5739    

DOI:10.1080/014957399280805

出版商:Informa UK Ltd    

年代:1999

数据来源: Taylor

摘要:

Developments in piezothermoelasticity having relevance to intelligent structures are discussed briefly. The equations governing the axisymmetric behavior of a piezoelastic body with hexagonal material symmetry of class 6 mm are reviewed. A general solution procedure based upon potential functions is presented for the analysis of transversely isotropic thermoelastic and piezothermoelastic bodies. The method is used to derive exact solutions to problems involving the response of a composite circular plate consisting of a piezoelectric material attached to a layer of structural material. Numerical results are presented for cases of: (i) a prescribed thermal loading; (ii) an inverse problem in which the thermal loading is determined from knowledge of induced electric potential; (iii) a control problem in which an electric potential is applied to control thermally induced deformation; and (iv) an intelligent plate problem, where the piezo electric layer serves both to sense the thermal loading and to suppress the deformation.

ISSN:0149-5739    

DOI:10.1080/014957399280814

出版商:Informa UK Ltd    

年代:1999

数据来源: Taylor

摘要:

The present contribution exhibits in a rational manner the progress recently achieved in the understanding of the canonical formulation of thermoelasticity on the material manifold. This formulation places in evidence the critical role played by the notion of material Eshelby stress in an equation that exhibits original source terms due to thermal effects, either in the bulk or at moving interfaces. Thermal effects are manifested here as quasi-inhomogeneity effects. This formulation captures well field singularities and in fact allows for the thermomechanical formulation of forces driving defects. Such a formulation also applies directly to devising a thermodynamically based numerical scheme using the notion of Schottky discrete systems.

ISSN:0149-5739    

DOI:10.1080/014957399280823

出版商:Informa UK Ltd    

年代:1999

数据来源: Taylor

摘要:

This is a survey article on the modeling of thermoelastic waves in a solid body. The term ''Generalized Thermoelasticity'' stands for a Hyperbolic Thermoelasticity in which a thermomechanical load applied to a body is transmitted in a wave-like manner throughout the body. Only transient thermoelastic waves are included in the survey. The modeling covers: (i) L-S model (Lord and Shulman, 1967), (ii) G-L model (Green and Lindsay, 1972), (iii) H-I model (Hetnarski and Ignaczak, 1996), (iv) G-N model (Green and Naghdi, 1993), and (v) C-T model (Chandrasekharaiah and Tzou, 1998). Attention focuses on the theoretical and practical significance of these models. Theoretical results include the domain of influence theorems, uniqueness as well as one-dimensional closed-form solutions. Except for a limiting case when the models reduce to rigid heat conductors, none of the five models has been verified by a combined thermoelastic experiment up to date, so their applications to real thermoelastic bodies present a challenge for future generations of researchers in the field.

ISSN:0149-5739    

DOI:10.1080/014957399280832

出版商:Informa UK Ltd    

年代:1999

数据来源: Taylor

摘要:

The thermal stress problems of functionally graded materials (FGMs), as one of the advanced high-temperature materials capable of withstanding the extreme temperature environments, are discussed. The FGMs consist of the continuously changing composi tion of two different materials. For example, one is an engineering ceramic to resist the severe thermal loading from the high-temperature environment, and the other is a light metal to maintain the structural rigidity. When the FGMs are subjected to extremely severe thermal loading, large thermal stresses are produced in the FGMs. Therefore, one of the most important problems of FGMs is how to decrease thermal stresses and how to increase heat resistance. The optimal composition profile problems of the FGMs in decreasing thermal stresses are discussed in detail. When FGMs are subjected to extremely severe thermal loading, the FGMs are damaged. The crack initiates on the ceramic surface and propagates in the FGMs. It is important to discuss the thermal stresses in the FGMs with various types of cracks. The thermal stress intensity factors in the FGMs with various types of crack are treated analytically and numerically. The optimal composition profile problems of the FGMs in decreasing thermal stress intensity factor are studied. Finally, the crack propagation paths due to thermal shock are discussed.

ISSN:0149-5739    

DOI:10.1080/014957399280841

出版商:Informa UK Ltd    

年代:1999

数据来源: Taylor

摘要:

Thermoelastic deformations can have a significant effect on the contact between elastic bodies, particularly in cases where the thermal boundary conditions at the interface are influenced by the contact pressure. In the classical Hertzian problem, the size of the contact area depends on the magnitude and direction of heat flow between the bodies. Idealized thermal boundary conditions can lead to ill-posed steady-state problems, but this difficulty is resolved by assuming a pressure-dependent thermal contact resistance. Steady states of the system can be unstable even when they are unique, in which case the behavior is either oscillatory or involves the steady motion of a contact pressure wave along the interface. Analytical and numerical perturbation methods have been developed to investigate the stability problem. These results find applications in heat transfer processes involving solid-solid contact, including the solidification of castings. In brakes and clutches, the heat generated at the sliding interface causes thermal distortion leading to ''frictionally excited thermoelastic instability'' or ''TEI,'' in which contact becomes localized in ''hot spots'' at the interface. Recent results enable us to make good predictions of the conditions under which this occurs.

ISSN:0149-5739    

DOI:10.1080/014957399280850

出版商:Informa UK Ltd    

年代:1999

数据来源: Taylor