摘要:

A two-dimensional numerical model is given for the analysis of the coupled thermal and mechanical behavior of the solidifying shell within the mold during continuous casting of steel. The influence of different mold wall profiles on gap formation and heat flow during casting of billets is investigated. The calculated temperatures, stresses, and strains in the shell are used to estimate the risk for formation of longitudinal cracks. The effect of an initiated and growing macroscopic subsurface crack on the shell behavior is studied. The genesis of surface cracks is discussed. The calculated results are shown to be in reasonable agreement with experimental observations reported in the literature.

ISSN:0149-5739    

DOI:10.1080/01495738408942209

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

This paper develops an algorithmic solution strategy which allows the handling of positive/indefinite stiffness characteristics associated with the pre- and post-buckling of structures subject to complex thermomechanical loading fields. The flexibility of the procedure is such that it can be applied to both finite difference and element-type simulations. Due to the generality of the algorithmic approach developed, both kinematic and thermal/mechanical type material nonlinearity including inelastic effects can be treated. This includes the possibility of handling completely general thermomechanical boundary conditions. To demonstrate the scheme, the results of several benchmark problems is presented.

ISSN:0149-5739    

DOI:10.1080/01495738408942210

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Kirchhoff's type formula for a solution of a central system of field equations of thermoelasticity with finite wave speeds is established in the paper. The solution of the system (φ, θ), where φ and θ denote the thermoelastic displacement potential and temperature respectively, is expressed by surface integrals over the boundary of a thermoelastic solid whose kernels have the form of infinite series involving Bessel functions. Application of the formula to reduce the solution of an initial-boundary problem to that of a vector Fredholm integral equation of the first kind is outlined.

ISSN:0149-5739    

DOI:10.1080/01495738408942211

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

In this paper nonlinear thermal behaviors of polygonal plates have been investigated following a new approach. A conformal mapping technique has been employed in the investigation. Numerical results obtained for different polygons are given in tables and compared with other known results.

ISSN:0149-5739    

DOI:10.1080/01495738408942212

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Governing equations of a temperature-rate-dependent thermopiezoelectricity theory which predicts a finite speed of propagation of thermal signals are obtained. A uniqueness theorem for solutions, a variational principle of Hamilton-type, and a reciprocal theorem are deduced in the context of the linearized theory.

ISSN:0149-5739    

DOI:10.1080/01495738408942213

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

This paper presents a theoretical analysis of the elastic instability of truncated conical shells under combined uniform pressure and thermal loading. The problem is solved by applying a finite difference method to the Donnell-type shell equations with the effect of large prebuckling deflections taken into consideration. It is found that the interaction curve of the buckling loads changes drastically with the loading order for the shallow cones clamped to rigid end plates and constrained in the axial direction. This phenomenon is caused by a remarkable difference in the prebuckling deformation and the buckling pattern of each case with single load.

ISSN:0149-5739    

DOI:10.1080/01495738408942214

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Sodium-silicate glass consists of a SiO2network and Na ions, which can diffuse through the network. The network structure freezes, whenever the local temperature decreases below the glass transition temperature Tg. Depending on the cooling process, different nonuniform network structures can be frozen in, this being the reason for frozen deformations, stresses, and structurally induced Na distributions. These are calculated adopting the following constitutive model in which it is assumed, that glass behaves like a thermoelastic material for temperatures above Tgand like a (structurally) rigid one below Tg. For spherical symmetric cooling of glass spheres we calculate under the classical boundary conditions and certain smoothness assumptions at the moving interface between the thermoelastic and the frozen glass analytical expressions for the frozen deformations, stresses, and Na distributions, ft turns out that these distributions depend strongly on the cooling history, such that the frozen network density increases from the center to the surface, the Na density decreases and the stress distributions decrease from strongly tensile at the center to slightly compressive at the surface of the sphere. Comparison of calculated and measured distributions show good agreement. The theoretically predicted and experimentally proven structurally induced Na diffusion might be of technical importance.

ISSN:0149-5739    

DOI:10.1080/01495738408942215

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The paper describes a creep analysis for prestressed concrete structures subjected to sustained or cyclically varying temperatures; cracking is not taken into account. Theory is presented for the general continuum problem and for continuous beam structures, ft is in such a form that the initial elastic and thermoelastic solutions, and the limiting or steady-state solution for creep, are obtained from the use of a single matrix equation. The solution at all stages of the problem is therefore ideally suited to a computer analysis. The calculation procedures are direct and time-step solutions are not required. The examples presented illustrate the combined influence of creep and nonuniform temperatures, and demonstrate the need to include a steady-state stress analysis at the design stage if long-term serviceability of prestressed concrete structures is to be assured. It is concluded that Codes of Practice should include sufficient information relating to temperature to permit an evaluation of long-term structural behavior to be made.

ISSN:0149-5739    

DOI:10.1080/01495738408942216

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

ISSN:0149-5739    

DOI:10.1080/01495738408942217

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor