摘要:

A numerical method is presented for evaluating the residual stress distribution in a long aluminum solid cylinder subjected to rapid cooling. An analytical model is developed for the temperature distribution. For the boundary conditions, experimental data for the outer surface of the cylinder are used, and a reasonable agreement between the predicted temperature distribution at the center of the cylinder and the experimental data is observed. For the numerical analysis, a quasi-static, uncoupled thermoelastoplastic analysis, based on a hyperbolic sine law, is presented. The numerical results are presented for the temperature distribution as well as the thermoelastoplastic stress distribution in a solid cylinder with temperature-dependent properties. The residual stress distribution is compared with the results of other investigators who used the Finite Element Method, and a reasonable agreement between our results and previous results is observed. The conclusion is reached that the temperature dependency of the yield stresses and the problem of post-yielding are two important factors to be considered when developing a model for predicting the residual stresses in quenched bodies.

ISSN:0149-5739    

DOI:10.1080/01495739608946192

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Based on three-dimensional elasticity without making static and kinematic assumptions, an asymptotic theory is formulated for thermoelastic analysis of doubly curved laminated shells. The laminated shell is regarded as a heterogeneous shell with nonhomogeneous material properties in the thickness direction. The bending of the shell subjected to temperature variations through the thickness and under lateral loads is considered. Upon introducing a small perturbation parameter in the formulation and rearranging the three-dimensional equations in dimensionless forms, it is shown that the problem can be treated systematically by means of asymptotic expansions and successive integration. The classical laminated shell (CST) equations are derived as the leading-order approximation to the three-dimensional theory. The higher order corrections are determined by solving the CST equations in a consistent and hierarchic manner. Illustrative examples are given to demonstrate the performance of the theory.

ISSN:0149-5739    

DOI:10.1080/01495739608946193

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Thermal stresses on a ground surface are one of the main concerns during surface grinding. The purpose of this article is to investigate the three-dimensional thermal stresses induced by grinding represented by a moving triangular heat source. The solutions of transient thermal stresses are derived by the Goodier's thermoelastic potential and Galerkin functions. The stresses are calculated numerically by the inverse Fourier transformation and integration of Simpson's 3/8 rule. Results show that the stress in the direction of the grinding depth is compressive and larger than the tensile stress along the feed direction. The stresses near the grinding zone change drastically. The workpiece feedrate is the main factor affecting the normal stresses. Cooling is essential in surface grinding, which can effectively reduce the normal stresses to zero or perhaps to negative value.

ISSN:0149-5739    

DOI:10.1080/01495739608946194

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Residual stresses present in an as-received and thermally cycled SCS-6/TI-15/3 metal matrix composite (MMC) have been examined via X-ray diffraction (sin2ψ) experiments. The determination of stress profiles has been achieved by successive removal of the matrix from the composite surface by electropolishing. Axial and hoop stresses in the matrix were tensile (stress levels were higher on the surface of the composite), and those measured in the fiber were compressive (−500 MPa to −600 MPa, but only a few measurements were possible). A stress gradient normal to the surface of the composite was found. Measurement of residual stress levels in the composite subjected to thermal cycling from 400°C to 800°C in an inert atmosphere or in vacuum-revealed significant stress relaxation after only 200 cycles.

ISSN:0149-5739    

DOI:10.1080/01495739608946195

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

In this section, publications on thermal stresses that have appeared elsewhere are listed. In order to make the list as complete as possible, authors are requested to submit two copies of their publications to the Editor-in-Chief. Publications in languages other than English should be accompanied by the English translation of their titles.

ISSN:0149-5739    

DOI:10.1080/01495739608946196

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor