摘要:

Two thermomechanical models of pure metal solidification on a sinusoidal mold surface are developed using a linear perturbation technique. In the first model, the mold surface temperature is held constant; while in the second model, the heat flux through the mold-shell interface is held constant. In both cases, the ratio of the mold surface amplitude to the wavelength is taken as the perturbation parameter and the models are thus limited to low aspect ratio surfaces that are perfectly wetted by the molten liquid. Mechanical distortion of the metal shell due to nonuniform heat flow through the spatially oscillatory mold-shell interface causes a change in the contact pressure along the interface. Both models show that the contact pressure increases at the crests of the mold surface while simultaneously decreasing in the troughs. This suggests a possible growth instability since micro-air gaps may nucleate in the mold surface troughs rather than at the crests, thereby reducing heat extraction beneath the thinnest regions of the shell and exaggerating its undulatory macromorphology. A method for generalizing both models for an arbitrary periodic mold surface topography, f( x), is also presented. Finally, the surface waviness of the metal shell is calculated after solidification ends and the shell is released from a mold with a purely sinusoidal surface topography.

ISSN:0149-5739    

DOI:10.1080/014957399280931

出版商:Informa UK Ltd    

年代:1999

数据来源: Taylor

摘要:

A three-dimensional analytical solution is presented for a simply supported, cross-ply, rectangular laminated composite plate, with some piezoelectric layers, subjected to any thermoelectromechanical load. The method of solution for inverse problems of inferring the applied temperature or pressure field from measured electrical potential difference is also presented. The solution is used to study the effectiveness of various actuating schemes for shape control of hybrid plates under thermomechanical load. The feasibility of reducing stresses due to pressure and thermal load by actuating a piezoelectric layer is reported.

ISSN:0149-5739    

DOI:10.1080/014957399280940

出版商:Informa UK Ltd    

年代:1999

数据来源: Taylor

摘要:

The exact solution is derived for the problem of uniformly heating a cylinder whose elastic moduli and thermal expansion coefficient vary linearly with radius. The solution shows that the radial and tangential stresses are largest in magnitude at the center of the cylinder whereas the deviatoric stress is largest in magnitude at the outer edge of the cylinder. The effective thermal expansion coefficient is found to be essentially given by the volumetric average of the local thermal expansion coefficient, with the variation in moduli having only a small effect. In the case of a material with uniform moduli but a spatially variable thermal expansion coefficient, the effective thermal expansion coeffi cient is exactly equal to the volumetric average; this result is an extension of those derived by Levin and Schapery for n-component materials.

ISSN:0149-5739    

DOI:10.1080/014957399280959

出版商:Informa UK Ltd    

年代:1999

数据来源: Taylor

摘要:

A problem of an elliptical rigid inclusion in an infinite plane subjected to uniform heat flux in an arbitrary direction and with a number of debondings on the interface of the elliptical rigid inclusion and the elastic matrix is solved. The rotation of the inclusion under the uniform heat flux is considered. The complex variable method is used, and the closed-form solution is obtained. The stress intensity of debonding at the debonding tips is calculated and the extension of debonding is investigated. Examples of stress distributions and resultant moments on the inclusion are shown for the inclusion with two debondings.

ISSN:0149-5739    

DOI:10.1080/014957399280968

出版商:Informa UK Ltd    

年代:1999

数据来源: Taylor

摘要:

A theory of thermoelasticity without energy dissipation has recently been initiated. Its evolution equations are hyperbolic. In this article we study the spatial behavior of solutions of the linear problem. We prove spatial estimates that are similar to those obtained in other theories of a hyperbolic type.

ISSN:0149-5739    

DOI:10.1080/014957399280977

出版商:Informa UK Ltd    

年代:1999

数据来源: Taylor

摘要:

The Cosserat Spectrum theory is briefly summarized and applied to two-dimensional thermoelasticity. The discrete Cosserat eigenvalues and eigenvectors of the first bound ary value problem for a solid cylinder and a cylindrical rigid inclusion in an infinite space are derived. The problem of uniform heat flow past a cylindrical cavity is reviewed within the frame of the Cosserat Spectrum theory. The displacement fields caused by an arbitrary harmonic temperature field and a nonharmonic heat source around a cylindrical rigid inclusion are solved by the Cosserat Spectrum theory.

ISSN:0149-5739    

DOI:10.1080/014957399280986

出版商:Informa UK Ltd    

年代:1999

数据来源: Taylor

摘要:

We derive nonstatic two-dimensional differential equations of heat conduction in multilayered anisotropic shells with corresponding boundary conditions assuming a cubic and linear temperature distribution in the thickness of each shell. The nonideal thermal contact (thermoresistance) between layers is considered. As an example we study the problem of temperature field distribution in a two-layered cylindrical shell of finite length under local heating.

ISSN:0149-5739    

DOI:10.1080/014957399280995

出版商:Informa UK Ltd    

年代:1999

数据来源: Taylor

ISSN:0149-5739    

DOI:10.1080/014957399281002

出版商:Informa UK Ltd    

年代:1999

数据来源: Taylor

ISSN:0149-5739    

DOI:10.1080/014957399281011

出版商:Informa UK Ltd    

年代:1999

数据来源: Taylor