scholarly journals Thermal Stresses in a Long Solid Cylinder with Temperature-Dependent Properties

1965 ◽  
Vol 31 (221) ◽  
pp. 9-15 ◽  
Author(s):  
Takashi KOIZUMI ◽  
Chikara TANIWAKI
Author(s):  
Mohamed Abdelsabour Fahmy

AbstractThe main aim of this article is to develop a new boundary element method (BEM) algorithm to model and simulate the nonlinear thermal stresses problems in micropolar functionally graded anisotropic (FGA) composites with temperature-dependent properties. Some inside points are chosen to treat the nonlinear terms and domain integrals. An integral formulation which is based on the use of Kirchhoff transformation is firstly used to simplify the transient heat conduction governing equation. Then, the residual nonlinear terms are carried out within the current formulation. The domain integrals can be effectively treated by applying the Cartesian transformation method (CTM). In the proposed BEM technique, the nonlinear temperature is computed on the boundary and some inside domain integral. Then, nonlinear displacement can be calculated at each time step. With the calculated temperature and displacement distributions, we can obtain the values of nonlinear thermal stresses. The efficiency of our proposed methodology has been improved by using the communication-avoiding versions of the Arnoldi (CA-Arnoldi) preconditioner for solving the resulting linear systems arising from the BEM to reduce the iterations number and computation time. The numerical outcomes establish the influence of temperature-dependent properties on the nonlinear temperature distribution, and investigate the effect of the functionally graded parameter on the nonlinear displacements and thermal stresses, through the micropolar FGA composites with temperature-dependent properties. These numerical outcomes also confirm the validity, precision and effectiveness of the proposed modeling and simulation methodology.


1991 ◽  
Vol 44 (9) ◽  
pp. 383-397 ◽  
Author(s):  
Naotake Noda

The present review on thermal stresses in materials with temperature-dependent properties focuses on papers published after 1980. The thermal and mechanical properties in materials subjected to thermal loads due to high temperature, high gradient temperature, and cyclical changes of temperature are dependent on temperature. The main theme of the thermoelastic problems in materials and structures with temperature-dependent material properties is to establish analytical procedures to solve the governing differential equations. In the thermo-inelastic problems, however, we must perform more accurate analysis of the practical problems (weld, heat treatment, metal forming, etc) taking account of the temperature-dependent material properties by use of numerical procedures (finite element methods, mainly).


2004 ◽  
Vol 261-263 ◽  
pp. 489-494 ◽  
Author(s):  
Meng Kao Yeh ◽  
C.Y. Tsai

The material properties of underfill and substrate in flip chip package have temperature-dependent and moisture-sensitive characteristics. During the solder reflow process, the CTE mismatch in the package causes thermal stresses, which may reduce the reliability of the flip chip package. The package reliability can be improved by varying the die thickness, the fillet angle and the thickness of the underfill and by changing the underfill material. In this paper, the temperature- dependent properties of the underfill were established first. The flip chip reliability was then analyzed by finite element code ANSYS. Both underfill A and underfill B were used in the analysis. The results show that better reliability of the flip chip package was obtained for underfill A, for larger fillet angle of the underfill, for thinner die in the package, and for larger Young's modulus of underfill with linear elastic assumption. Also a hygrothermal preconditioning before thermal cycling reduces the reliability of the flip chip package.


Author(s):  
Shahriar Jahanian

Abstract There are many practical instances of structural behaviors where the incremental increase of deformation occurs under cyclic loading, such as ratcheting in nuclear fuel element cans, incremental growth of pressure vessels or turbine cases, etc. This increase of deformation may lead to the failure of structure. For an incremental collapse to occur, it is necessary for different parts of the structure to yield at different stages of loading and unloading cycle. When the thermal loading is present, the properties of the material are temperature dependent. Accordingly the yielding occur at the earlier stage. The situation may get worse when the thermal loading is coupled with the mechanical one. This paper presents a quasi-static, uncoupled thermo-elastoplastic analysis based on incremental theory of plasticity. The behavior of a solid cylinder subjected to torsion and transient thermal loading for one cycle is investigated. The influence upon behavior of nonlinear-strain hardening in the material is investigated.


1961 ◽  
Vol 28 (2) ◽  
pp. 193-207 ◽  
Author(s):  
Rokuro Muki ◽  
Eli Sternberg

This paper deals with the quasi-static analysis of transient thermal stresses in the linear theory of viscoelastic solids with temperature-dependent properties. The underlying constitutive law rests on the temperature-time equivalence hypothesis. Following an exposition of the theoretical framework exact solutions to two specific problems are deduced: The first concerns the thermal stresses in a slab of infinite extent, generated by a temperature field that depends arbitrarily on the thickness co-ordinate and time; the second application concerns the stresses produced in a sphere by an arbitrary time-dependent radially symmetric temperature distribution. The numerical illustrations of the results obtained include a quantitative study based on actual test data for a polymethyl methacrylate.


1964 ◽  
Vol 31 (1) ◽  
pp. 47-53 ◽  
Author(s):  
K. C. Valanis ◽  
George Lianis

This paper is concerned with a perturbation technique suitable for the stress analysis of viscoelastic solids with temperature-dependent properties in the presence of nonuniform transient temperature fields. The problems of the infinite slab, solid sphere, and infinitely long viscoelastic cylinder are given solutions in the form of infinite series. Sufficient conditions for the convergence of the series are established.


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