Axisymmetric problem of the steady-state thermal stresses in elastic media with temperature dependent properties

1964 ◽  
Vol 12 (4-5) ◽  
pp. 349-377 ◽  
Author(s):  
J. Nowinski
Keyword(s):  
Steady State ◽  
Axisymmetric Problem ◽  
Thermal Stresses ◽  
Elastic Media ◽  
Temperature Dependent ◽  
Temperature Dependent Properties

scholarly journals A new boundary element algorithm for modeling and simulation of nonlinear thermal stresses in micropolar FGA composites with temperature-dependent properties

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Mohamed Abdelsabour Fahmy
Keyword(s):  
Modeling And Simulation ◽  
Boundary Element ◽  
Thermal Stresses ◽  
Computation Time ◽  
Functionally Graded ◽  
Temperature Dependent ◽  
Time Step ◽  
Kirchhoff Transformation ◽  
Nonlinear Temperature ◽  
Temperature Dependent Properties

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.

Thermal Stresses in Materials with Temperature-Dependent Properties

1991 ◽  
Vol 44 (9) ◽  
pp. 383-397 ◽  
Author(s):  
Naotake Noda
Keyword(s):  
Mechanical Properties ◽  
Material Properties ◽  
Metal Forming ◽  
Thermal Stresses ◽  
Main Theme ◽  
Thermal And Mechanical Properties ◽  
Temperature Dependent ◽  
Accurate Analysis ◽  
Thermoelastic Problems ◽  
Temperature Dependent Properties

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).

Reliability Analysis in Flip Chip Package under Thermal Cycling

2004 ◽  
Vol 261-263 ◽  
pp. 489-494 ◽  
Author(s):  
Meng Kao Yeh ◽  
C.Y. Tsai
Keyword(s):  
Thermal Cycling ◽  
Flip Chip ◽  
Thermal Stresses ◽  
Temperature Dependent ◽  
Linear Elastic ◽  
Cte Mismatch ◽  
Sensitive Characteristics ◽  
Moisture Sensitive ◽  
Temperature Dependent Properties ◽  
Package Reliability

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.

Transient Response in a Viscoelastic Material With Temperature-Dependent Properties and Thermomechanical Coupling

1965 ◽  
Vol 32 (3) ◽  
pp. 620-622 ◽  
Author(s):  
R. M. Wolosewick ◽  
Serge Gratch
Keyword(s):  
Steady State ◽  
Physical Properties ◽  
Temperature Dependence ◽  
Transient Response ◽  
Polymeric Materials ◽  
Thermomechanical Coupling ◽  
Stress And Strain ◽  
Temperature Dependent ◽  
Stress Variation ◽  
Temperature Dependent Properties

The transient response of a semi-infinite, viscoelastic rod after application of a sinusoidal stress variation at one end has been investigated by a numerical method. Account has been taken of temperature dependence of properties and of thermomechanical coupling. It is found that, with values of physical properties typical for polymeric materials, temperature approaches steady state several orders of magnitude more slowly than would be the case for stress and strain in the absence of thermomechanical coupling.

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