scholarly journals The Propagation of Thermal Stresses in a Semi-infinite Medium

1960 ◽  
Vol 12 (2) ◽  
pp. 75-84 ◽  
Author(s):  
F. J. Lockett
Keyword(s):  
Dynamical System ◽  
Thermal Effects ◽  
Thermal Stresses ◽  
Elastic Solid ◽  
Infinite Medium ◽  
Heat Energy ◽  
The Body ◽  
Heat Sources ◽  
Surface Temperature Distribution ◽  
Work Done

When an elastic solid is subjected to a dynamical system of surface or body forces, not all of the work done by these forces is employed in deforming the material. The remainder is converted into heat energy producing a distribution of temperature throughout the body. Similarly the application of a surface temperature distribution, or the introduction of heat sources within the body, produces elastic as well as thermal effects. Thus we see that in the dynamical case there is a link between these two types of condition—thermal and elastic.

scholarly journals Propagation of Thermal Stresses in an Infinite Medium

1959 ◽  
Vol 11 (4) ◽  
pp. 237-244 ◽  
Author(s):  
F. J. Lockett ◽  
I. N. Sneddon
Keyword(s):  
Thermal Stresses ◽  
Infinite Medium ◽  
Nonuniform Distribution ◽  
The Body ◽  
Heat Sources ◽  
Dynamic Stresses ◽  
Elastic Bodies ◽  
State Of Stress ◽  
Body Forces ◽  
Uneven Heating

In the full linear theory of thermoelasticity there is a coupling between the thermal and the purely mechanical effects so that not only does a nonuniform distribution of temperature in the solid produce a state of stress but dynamical body forces or applied surface tractions produce variations in temperature throughout the body. In a recent paper (Eason and Sneddon, (2)) an account was given of the calculation of the dynamic stresses produced in elastic bodies, both infinite and semi-infinite, by uneven heating. In this paper we shall consider the propagation of thermal stresses in an infinite medium when, in addition to heat sources, there are present body forces which vary with the time.

scholarly journals Impact of 2.45 GHz Microwave Irradiation on the Fruit Fly, Drosophila melanogaster

Insects ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 598
Author(s):  
Aya Yanagawa ◽  
Masatoshi Tomaru ◽  
Atsushi Kajiwara ◽  
Hiroki Nakajima ◽  
Elie Desmond-Le Quemener ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Microwave Irradiation ◽  
Thermal Effects ◽  
Electromagnetic Waves ◽  
Travelling Waves ◽  
Fruit Fly ◽  
Travelling Wave ◽  
Heat Energy ◽  
The Body ◽  
Behavioral Alterations

The physiological and behavioral influences of 2.45 GHz microwaves on Drosophila melanogaster were examined. Standing waves transitioned into heat energy effectively when passing through the insect body. On the contrary, travelling waves did not transit into heat energy in the insect body. This indicated that there was no concern regarding the thermal effects of microwave irradiation for levels of daily usage. However, we detected genotoxicity and behavioral alterations associated with travelling wave irradiation, which can be attributed to the non-thermal effects of the waves. Electron spin resonance (ESR) revealed that fruit flies possessed paramagnetic substances in the body such as Fe3+, Cu2+, Mn2+, and organic radicals. The temperature dependent intensities of these paramagnetic substances indicated that females possessed more of the components susceptible to electromagnetic waves than males, and the behavioral tests supported the differences between the sexes.

PLANETARY SELF-ORGANIZATION

2020 ◽  
Vol 42 (3) ◽  
pp. 271-282
Author(s):  
OLEG IVANOV
Keyword(s):  
Dynamical System ◽  
Heat Source ◽  
Mantle Convection ◽  
Plate Tectonics ◽  
Rotation Speed ◽  
Self Organization ◽  
Heat Sources ◽  
Kinematic Parameters ◽  
The Earth ◽  
New Type

The general characteristics of planetary systems are described. Well-known heat sources of evolution are considered. A new type of heat source, variations of kinematic parameters in a dynamical system, is proposed. The inconsistency of the perovskite-post-perovskite heat model is proved. Calculations of inertia moments relative to the D boundary on the Earth are given. The 9 times difference allows us to claim that the sliding of the upper layers at the Earth's rotation speed variations emit heat by viscous friction.This heat is the basis of mantle convection and lithospheric plate tectonics.

scholarly journals Thermal Stresses in Chemically Hardening Elastic Media With Application to the Molding Process

1974 ◽  
Vol 41 (3) ◽  
pp. 647-651 ◽  
Author(s):  
Myron Levitsky ◽  
Bernard W. Shaffer
Keyword(s):  
Residual Stress ◽  
Chemical Reaction ◽  
Thermal Stresses ◽  
Stress Component ◽  
Elastic Solid ◽  
Molding Process ◽  
Hardening Process ◽  
Exothermic Chemical Reaction ◽  
Component Parallel

A method has been formulated for the determination of thermal stresses in materials which harden in the presence of an exothermic chemical reaction. Hardening is described by the transformation of the material from an inviscid liquid-like state into an elastic solid, where intermediate states consist of a mixture of the two, in a ratio which is determined by the degree of chemical reaction. The method is illustrated in terms of an infinite slab cast between two rigid mold surfaces. It is found that the stress component normal to the slab surfaces vanishes in the residual state, so that removal of the slab from the mold leaves the remaining residual stress unchanged. On the other hand, the residual stress component parallel to the slab surfaces does not vanish. Its distribution is described as a function of the parameters of the hardening process.

Study on Thermal Analysis of the Shape of Improved Electric Cooker Liner Based on ANSYS Workbench

2014 ◽  
Vol 487 ◽  
pp. 568-571
Author(s):  
Yan Li Su ◽  
Lei Li ◽  
Wei Guo Han
Keyword(s):  
Thermal Analysis ◽  
Thermal Stress ◽  
Stress Analysis ◽  
Thermal Effects ◽  
The Body ◽  
Total Deformation ◽  
Ansys Workbench

In this paper, a comparative thermal analysis is carried out according to the bottom of HR-FD51 electric cooker liner about a large or small fillet. And then the thermal analysis results are applied to stress analysis as the body loads. The results show that it can reduce thermal stress and total deformation with a large fillet, thereby, improves the lifespan of electric cooker liner and thermal effects as well.

Transient Temperature Involving Oscillatory Heat Source With Application in Fretting Contact

2007 ◽  
Vol 129 (3) ◽  
pp. 517-527 ◽  
Author(s):  
Jun Wen ◽  
M. M. Khonsari
Keyword(s):  
Heat Source ◽  
Oscillation Amplitude ◽  
The Body ◽  
Transient Temperature ◽  
Dimensionless Frequency ◽  
Heat Sources ◽  
Infinite Body ◽  
Fitting Method ◽  
Wide Range ◽  
Analytical Expressions

An analytical approach for treating problems involving oscillatory heat source is presented. The transient temperature profile involving circular, rectangular, and parabolic heat sources undergoing oscillatory motion on a semi-infinite body is determined by integrating the instantaneous solution for a point heat source throughout the area where the heat source acts with an assumption that the body takes all the heat. An efficient algorithm for solving the governing equations is developed. The results of a series simulations are presented, covering a wide range of operating parameters including a new dimensionless frequency ω¯=ωl2∕4α and the dimensionless oscillation amplitude A¯=A∕l, whose product can be interpreted as the Peclet number involving oscillatory heat source, Pe=ω¯A¯. Application of the present method to fretting contact is presented. The predicted temperature is in good agreement with published literature. Furthermore, analytical expressions for predicting the maximum surface temperature for different heat sources are provided by a surface-fitting method based on an extensive number of simulations.

scholarly journals Broiler surface temperature distribution of 42 day old chickens

2010 ◽  
Vol 67 (5) ◽  
pp. 497-502 ◽  
Author(s):  
Irenilza de Alencar Nääs ◽  
Carlos Eduardo Bites Romanini ◽  
Diego Pereira Neves ◽  
Guilherme Rodrigues do Nascimento ◽  
Rimena do Amaral Vercellino
Keyword(s):  
Temperature Distribution ◽  
Surface Temperature ◽  
Air Temperature ◽  
Broiler Chickens ◽  
Broiler Chicken ◽  
Growth Period ◽  
The Body ◽  
Body Parts ◽  
Surface Temperature Distribution ◽  
Thermographic Image

Broiler chickens in Brazil are generally reared from 1 to 42 days when they are exposed to procedures such as fasting, harvesting, crating and transport to slaughter. Maintaining homeostasis is of great importance for broiler survival under harsh environment especially prior to slaughter. Heat loss varies in the distinct parts of the body during the growth period, and it is related to the air temperature of the environment and to the amount of feather covering. This research aimed to study the surface temperature distribution using infrared thermographic image processing to characterize 42 day old broiler chicken surface temperature prior to slaughter. Broilers were reared for 42 days and prior to harvest and transport to slaughter the infrared surface temperature was recorded along the day. Data from the thermograms taken in feather and featherless regions were compared during the 42nd day of growth. High correlation between featherless regions and air temperature was found showing that these areas respond fast to changes in the rearing environment. Two functions were developed for predicting both surface temperature for featherless and feather covered areas of the broiler body parts.

Stresses Due to Tangential and Normal Loads on an Elastic Solid With Application to Some Contact Stress Problems

1953 ◽  
Vol 20 (2) ◽  
pp. 157-166
Author(s):  
J. O. Smith ◽  
Chang Keng Liu
Keyword(s):  
Plane Strain ◽  
Coefficient Of Friction ◽  
Contact Area ◽  
Normal Load ◽  
Elastic Solid ◽  
Real Variable ◽  
The Body ◽  
Shearing Stress ◽  
Tangential Load ◽  
The Coefficient Of Friction

Abstract The results of two-dimensional approach using real variable method to Hertz’s problem of contact of elastic bodies are presented. Both normal and tangential loads are assumed to be distributed in Hertzian fashion over the area of contact. The magnitude of the intensity of the tangential load is assumed to be linearly proportional to that of the normal load when sliding motion of the body is impending. The stresses in the elastic body due to the application of these loads on its boundary are presented in closed form for both plane-stress and plane-strain cases. A numerical value of f = 1/3 is assumed for the linear proportionality (coefficient of friction) between the tangential and normal loads in order that the distribution of stresses may be illustrated. The significance of the stress distribution, across the contact area and in the body, is also discussed. It is shown that when the combination of loads considered in the paper are applied at the contact area of bodies in contact the maximum shearing stress may be at the surface instead of beneath the surface. For example, for plane strain, if the coefficient of friction is f = 1/3, the maximum shearing stress is at the surface and is 43 per cent larger than the maximum shearing stress, which would be below the surface, that occurs when the normal force acts alone. The effect of range of normal stress and of shearing stress on the plane of maximum shear and on the plane of maximum octahedral shear on failure by progressive fracture (fatigue) is discussed.

Sign in / Sign up

Export Citation Format

Share Document