摘要:

The state space approach to generalized thermoelasticity is reformulated, and it is established that the solutions to the generalized thermoelastic fields can be formed by an entirely different approach as was illustrated by Sosa and Baharfor coupled thermoelastic problems. The article is concerned with a one-dimensional description of a semi-infinite body subjected to two types of boundary conditions; namely: (i)a step input of temperature and zero stress and(ii) a step input of stress and zero temperature. The various results obtained are found to be discontinuous for certain values of time in both the Lord and Shulman and the Green and Lindsay theories of thermoelasticity, and most of the jumps are shown to decay exponentially with time. The results for conventional coupled theory of thermoelasticity are obtained as a particular case of the generalized theory.

ISSN:0149-5739    

DOI:10.1080/01495739708956094

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

The reflection and refraction of thermoelastic waves at an interface of two semi-infinite media in contact with two relaxation times are studied following Green and Lindsay's theory. The analytical expressions for the partition of energy are carried out. The results for various values of the angle of incidence for the partition of energy are presented in the context of two different cases: (i) liquid-liquid and (ii) liquid-solid. The numerical results are represented graphically to aid the comparison with Lord and Shulman's theory in order to see the effect of the second relaxation time.

ISSN:0149-5739    

DOI:10.1080/01495739708956095

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

In this article we derive the basic equations of a nonlinear theory for binary mixtures of elastic materials in which the constituents may have different temperatures. The independent constitutive variables are the displacement fields, the first displacement gradients, the temperatures of the constituents, and the temperature gradients. The basic equations of the linear theory are established, and the displacement-temperature equations in the case of homogeneous and isotropic materials are derived.

ISSN:0149-5739    

DOI:10.1080/01495739708956096

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

Conductive heat transfer across an interface between two different materials can be unstable due to the interaction between thermoelastic distortion, contact pressure, and thermal contact resistance. This article investigates the stability of a system consisting of two layers in contact by using a perturbation method. Results are presented for several different material combinations. Most cases exhibit instability only for heat flow into the more distortiue material; but for some material combinations, instability can occur for either direction of heat flow. In all cases, instability is associated with a sinusoidal perturbation whose wavelength is about twice the layer thickness, except for cases of very low interface resistance when wavelengths as small as the layer thickness can be obtained.

ISSN:0149-5739    

DOI:10.1080/01495739708956097

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

The frictional heat generated during braking causes thermoelastic distortion that modifies the contact pressure distribution. If the sliding speed is sufficiently high, this can lead to frictionalfy excited thermoelastic instability, characterized by major nonuniformi-ties in pressure and temperature. In automotive applications, a particular area of concern is the relation between thermoelasticalfy induced hot spots in the brake disks and noise and vibration in the brake system. The critical sliding speed can be found by examining the conditions under which a perturbation in the temperature and stress fields can grow in time. The growth has exponential character, and subject to certain restrictions, the growth rate b is found to be real. The critical speed then corresponds to a condition at which b = 0 and hence at which there is a steady-state solution involuing nonuniform contact pressure. We first treat the heat sources Q at the contact nodes as given and use standard finite element analysis (FEA) to determine the corresponding nodal contact forces P. The heat balance equation Q =fVP, where f is the coefficient of friction, then defines a linear eigenvalue problem for the critical speed V. The method is found to give good estimates for the critical speed in test cases with a relatively coarse mesh. It is generally better conditioned and more computationally efficient than a direct finite element simulation of the system in time. Results are presented for several examples related to automotive practice and show that theflexural rigidity of the friction pad assembly has a major effect on the critical speed.

ISSN:0149-5739    

DOI:10.1080/01495739708956098

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

In this article, we consider a circular plate and discuss the transient thermoelastoplastic bending problems making use of the strain increment theorem. In order to develop the analysis for the temperature field, we introduce the methods of generalized finite Fourier transform and finite Hankel transform. And for the theoretical analysis of thermoelastoplastic deformation of the plate, we treat the problem as plate bending, which is usually applied to the analysis of thermoelastic deformation. For the thermoelastic deformation, the analytical solution is obtained. On the other hand, for the plastic deformation, the solution is evaluated with the aid of the finite difference method. For the numerical calculations, the strain increment is calculated by successive elastic solution. Some numerical results are shown graphically.

ISSN:0149-5739    

DOI:10.1080/01495739708956099

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor