scholarly journals Thermal Stresses in Porous Materials under Thermal Shock by Cooling Medium-Infiltration Effect on Thermal Stress Distributions-

2004 ◽  
Vol 112 (1303) ◽  
pp. 172-178 ◽  
Author(s):  
Hiroaki TANAKA ◽  
Yuji MAKI ◽  
Kazuki TSUBOI ◽  
Sawao HONDA ◽  
Tadahiro NISHIKAWA ◽  
...  
Author(s):  
Mohamed Abdelsabour Fahmy

The main objective of this chapter is to introduce a novel memory-dependent derivative (MDD) model based on the boundary element method (BEM) for solving transient three-temperature (3T) nonlinear thermal stress problems in functionally graded anisotropic (FGA) smart structures. The governing equations of the considered study are nonlinear and very difficult if not impossible to solve analytically. Therefore, we develop a new boundary element scheme for solving such equations. The numerical results are presented highlighting the effects of the MDD on the temperatures and nonlinear thermal stress distributions and also the effect of anisotropy on the nonlinear thermal stress distributions in FGA smart structures. The numerical results also verify the validity and accuracy of the proposed methodology. The computing performance of the proposed model has been performed using communication-avoiding Arnoldi procedure. We can conclude that the results of this chapter contribute to increase our understanding on the FGA smart structures. Consequently, the results also contribute to the further development of technological and industrial applications of FGA smart structures of various characteristics.


2011 ◽  
Vol 230-232 ◽  
pp. 1345-1349 ◽  
Author(s):  
Cun Jun Chen ◽  
Min You ◽  
Hai Zhou Yu ◽  
Jian Li Li ◽  
Chun Zhi Mei

The temperature field in the adhesively bonded single lap steel joint after a thermal shock (100 °C, 10s) and the influence of the restraint on the thermal stress in the joint was investigated using elasto-plastic finite element method (FEM). The results showed that the temperature in the overlap region is symmetrically distributed to the bondline after the thermal shock. Five kinds of constraints were applied in the study and it is found that the peak value of the thermal stresses were occurred at the points near the free ends of the adherend lap zone along the mid-bondline under the action of constraining the adherends in the direction of both transversal and longitudinal. The symbol of the longitudinal stress Sx and peel stress Sy is negative.


2016 ◽  
Vol 22 (2) ◽  
pp. 243-256
Author(s):  
Amir Reza Shahani ◽  
Samad Kalani

Temperature and thermal stress distributions in a two-dimensional infinite thin plate subjected to a moving heat source with variable power and velocity are obtained by solving quasi-static thermoelasticity equations analytically with the aid of a thermoelastic displacement potential. The results show good agreement with experimental data for a stationary source with constant power and with a steady-state analytical solution in the open literature. It is shown that the quasi-static solution can predict changes of the thermal stress field during the movement of the heat source, and can give the effect of changes of power and velocity of the heat source on the thermal stress field during its movement.


1990 ◽  
Vol 25 (1) ◽  
pp. 9-14 ◽  
Author(s):  
Y Ochiai ◽  
R Ishida ◽  
T Sekiya

A numerical method to analyse unsteady thermal stresses in three-dimensional problems is proposed. It is shown that three-dimensional unsteady thermal stress problems can be easily solved without the volume integral by means of the thermoelastic displacement potential and the boundary element method. It is also shown that the time integral can be easily carried out analytically. In order to investigate the accuracy of this method, unsteady thermal stress distributions for a sphere and a circular cylinder are obtained. As a numerical example for which it is difficult to obtain the analytical solution, thermal displacements and surface stress distributions for a torus are obtained.


1961 ◽  
Vol 28 (3) ◽  
pp. 409-416 ◽  
Author(s):  
W. G. Flieder ◽  
J. C. Loria ◽  
W. J. Smith

The design of propellant loading systems for present-day missiles involves the design of pipelines that can carry cryogenic fluids and requires an additional consideration beyond the conventional analyses for flexibility and dead weight. Because of varying flow conditions and boil-off, these cryogenic lines experience varying fill levels and concomitant temperature gradients which cause these lines to bow; i.e., to assume a uniform curvature of circular arc. If constrained, the thermal-stress distributions which are generated by the temperature gradients will have superposed on them additional stresses, which result from the action of the support constraints. This combination of stresses may be critical and/or the loads on the supports may be excessive. The following analysis investigates these bowing effects, thermal stresses, and indicates the support problems entailed.


2011 ◽  
Vol 383-390 ◽  
pp. 2211-2215
Author(s):  
Chong Lue Hua ◽  
Gui Cheng Wang ◽  
Hong Jie Pei ◽  
Gang Liu

Thermal stresses of grinding plays an important role on the fatigue and wear resistance of the component. A comprehensive analysis of thermal stress induced by surface grinding has been conducted with aid of the finite element method. To obtain a reliable figure of thermal stress induced by grinding, temperature-dependent properties of workpiece materials were taken into account. The developed finite element procedure has also been applied to calculate the surface and sub-surface thermal stress induced by moving source of triangular heat when convection and radiation is occurred over the whole work. Based on an analysis of the effects of wheel velocity on the thermal stress distributions in an elastic-plastic solid, some important conclusions were given.


2010 ◽  
Vol 150-151 ◽  
pp. 873-876
Author(s):  
Dai Hui Tu ◽  
Yang Jian Xu ◽  
Jian Hui Jia

The steady thermal stress distributions and effect factors in a ZrO2/FGM/Ti-6Al-4V composite ECBC plate with temperature-dependent material properties under convective heat transfer boundary were investigated by the NFEM and the Sinpson method. From numerical calculation, when , T0=300K, Ta=350K and Tb=1 750K, the thermal stress distributions in the composite FGM plate were obtained. The results are as follows. With the increase of the FGM gradient layer thickness and when M=1, the temperature distributions in the composite plate are more reasonable. With the increase of the FGM gradient layer M, the thermal stresses on the ceramic surface tend toward reduction, and compared with the thermal stress of M=0.2, the thermal stress of M =5 reduces by 17.8%. When we take into account the effect of temperature-dependent material properties, compared with the results of constant material properties, the maximum compressive stress on the surface of metal reduces by 74.2%, and the maximum compressive stress on the surface of ceramics reduces by 45.3%. With the increase of FGM layer porosity P, the change of stress at the bonding interface of the three-layered plate increases, and the stress curves appear peak values. Compared with A=0, when A=3.99, the compressive thermal stress on the metal surface reduces by 42.0%, and the compressive thermal stress on the ceramic surface increases by 154.7%. Compared with the nongraded two-layered ceramic/metal composite plate, the thermal stress of the ZrO2/FGM/ Ti-6Al-4V composite plate is very gentle. Compared with , when , the maximum compressive stress on the surface of metal reduces by 49.98%, and the maximum compressive stress on the surface of ceramics increases by 182.3%. The results provide the foundations of theoretical calculation for the design and application of the composite plate.


Author(s):  
Jaan Taagepera ◽  
Marty Clift ◽  
D. Mike DeHart ◽  
Keneth Marden

Three vessel modifications requiring heat treatment were analyzed prior to and during a planned turnaround at a refinery. One was a thick nozzle that required weld build up. This nozzle had been in hydrogen service and required bake-out to reduce the potential for cracking during the weld build up. Finite element analysis was used to study the thermal stresses involved in the bake-out. Another heat treatment studied was a PWHT of a nozzle replacement. The heat treatment band and temperature were varied with location in order to minimize cost and reduction in remaining strength of the vessel. Again, FEA was used to provide insight into the thermal stress profiles during heat treatment. The fmal heat treatment study was for inserting a new nozzle in a 1-1/4Cr-1/2Mo reactor. While this material would ordinarily require PWHT, the alteration was proposed to be installed without PWHT. Though accepted by the Jurisdiction, this nozzle installation was ultimately cancelled.


1975 ◽  
Vol 97 (3) ◽  
pp. 1060-1066
Author(s):  
P. F. Thomason

Closed form expressions for the steady-state thermal stresses in a π/2 wedge, subject to constant-temperature heat sources on the rake and flank contact segments, are obtained from a conformal mapping solution to the steady-state heat conduction problem. It is shown, following a theorem of Muskhelishvili, that the only nonzero thermal stress in the plane-strain wedge is that acting normal to the wedge plane. The thermal stress solutions are superimposed on a previously published isothermal cutting-load solution, to give the complete thermoelastic stress distribution at the wedge surfaces. The thermoelastic stresses are then used to determine the distribution of the equivalent stress, and this gives an indication of the regions on a cutting tool which are likely to be in the plastic state. The results are discussed in relation to the problems of flank wear and rakeface crater wear in metal cutting tools.


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