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.

Wave Propagation in a Viscoelastic Material With Temperature-Dependent Properties and Thermomechanical Coupling

1964 ◽  
Vol 31 (3) ◽  
pp. 423-429 ◽  
Author(s):  
Robert C. Petrof ◽  
Serge Gratch
Keyword(s):  
Wave Propagation ◽  
Elastic System ◽  
Thermomechanical Coupling ◽  
Temperature Dependent ◽  
Stress Variation ◽  
Single Degree Of Freedom ◽  
One Dimensional ◽  
Stress Strain Relation ◽  
Longitudinal Wave Propagation ◽  
Temperature Dependent Properties

A numerical method is developed for the analysis of one-dimensional wave propagation in viscoelastic media with temperature-dependent properties when thermomechanical coupling is significant. The method is applied to a specific case of longitudinal wave propagation in a finite rod with essentially sinusoidal stress variation at the two ends. The results show that, contrary to the usual assumption, such a system does not have the same response as a single-degree-of-freedom elastic system with viscous damping, as long as a realistic stress-strain relation is used.

scholarly journals Temperature Dependence of Dielectric Properties of Ferroelectric Heterostructures with Domain-Provided Negative Capacitance

Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 75
Author(s):  
Maksim A. Pavlenko ◽  
Yuri A. Tikhonov ◽  
Anna G. Razumnaya ◽  
Valerii M. Vinokur ◽  
Igor A. Lukyanchuk
Keyword(s):  
Phase Diagram ◽  
Dielectric Properties ◽  
Temperature Dependence ◽  
Energy Efficient ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Negative Capacitance ◽  
Temperature Dependent ◽  
Domain Structures ◽  
Temperature Dependent Properties

It is well known that the ferroelectric layers in dielectric/ferroelectric/dielectric heterostructures harbor polarization domains resulting in the negative capacitance crucial for manufacturing energy-efficient field-effect transistors. However, the temperature behavior of the characteristic dielectric properties, and, hence, the corresponding behavior of the negative capacitance, are still poorly understood, restraining the technological progress thereof. Here we investigate the temperature-dependent properties of domain structures in the SrTiO3/PbTiO3/SrTiO3 heterostructures and demonstrate that the temperature–thickness phase diagram of the system includes the ferroelectric and paraelectric regions, which exhibit different responses to the applied electric field. Using phase-field modeling and analytical calculations we find the temperature dependence of the dielectric constant of ferroelectric layers and identify the regions of the phase diagram wherein the system demonstrates negative capacitance. We further discuss the optimal routes for implementing negative capacitance in energy-efficient ferroelectric field-effect transistors.

scholarly journals Dynamics of Rising Bubbles in a Quiescent Slag Bath with Varying Thermo-Physical Properties

2020 ◽  
Vol 51 (6) ◽  
pp. 2843-2861
Author(s):  
D. Obiso ◽  
D. H. Schwitalla ◽  
I. Korobeinikov ◽  
B. Meyer ◽  
M. Reuter ◽  
...  
Keyword(s):  
Physical Properties ◽  
Bubble Dynamics ◽  
Fluid Dynamic ◽  
Temperature Gradients ◽  
Slag Bath ◽  
Bubble Motion ◽  
Temperature Dependent ◽  
Slag Properties ◽  
Temperature Dependent Properties ◽  
Thermo Physical Properties

AbstractThe motion of bubbles in a liquid slag bath with temperature gradients is investigated by means of 3D fluid dynamic computations. The goal of the work is to describe the dynamics of the rising bubbles, taking into account the temperature dependency of the thermo-physical properties of the slag. Attention is paid to the modeling approach used for the slag properties and how this affects the simulation of the bubble motion. In particular, the usage of constant values is compared to the usage of temperature-dependent data, taken from models available in the literature and from in-house experimental measurements. Although the present study focuses on temperature gradients, the consideration of varying thermo-physical properties is greatly relevant for the fluid dynamic modeling of reactive slag baths, since the same effect is given by heterogeneous species and solid fraction distributions. CFD is applied to evaluate the bubble dynamics in terms of the rising path, terminal bubble shape, and velocity, the gas–liquid interface area, and the appearance of break-up phenomena. It is shown that the presence of a thermal gradient strongly acts on the gas–liquid interaction when the temperature-dependent properties are considered. Furthermore, the use of literature models and experimental data produces different results, demonstrating the importance of correctly modeling the slag’s thermo-physical properties.

A Transient Thermoelastoplastic Solution for a Hollow Sphere of Temperature Dependent Properties

1995 ◽  
Author(s):  
Shahriar Jahanian
Keyword(s):  
Hollow Sphere ◽  
Strain Distribution ◽  
Residual Stress Distribution ◽  
Stress And Strain ◽  
Linear Strain ◽  
Temperature Dependent ◽  
History Of ◽  
Temperature Dependent Properties ◽  
Stress And Strain Distribution ◽  
Incremental Theory Of Plasticity

Abstract In this paper an analysis based on incremental theory of plasticity is formulated to predict the thermoelastoplastic stresses in a hollow sphere. The properties of the material are assumed to be temperature dependent, and the material was characterized by linear strain hardening. Mendeson’s method of successive elastic solution is presented for the analysis. The analysis shows that the stresses are not monotonic function of radius or temperature, they strongly depend on history of temperature distribution. In this analysis the problem is treated in a uncoupled, and quasi-static sense. The plastic stress and strain distribution on loading and the residual stress distribution on unloading is presented. The results are compared with the results of other investigators who used a different theory and a reasonable agreement is observed.

Physical Properties of Textured Polyester Yarns: The Influence of Texturing Temperatures

1976 ◽  
Vol 46 (11) ◽  
pp. 828-833 ◽  
Author(s):  
G. L. Hardegree ◽  
D. R. Buchanan
Keyword(s):  
Thermal Stress ◽  
Physical Properties ◽  
Temperature Dependence ◽  
Temperature Curve ◽  
Temperature Dependent ◽  
Significant Dependence ◽  
Initial Modulus ◽  
Property Versus

The temperature dependence of textured yarn physical properties has been determined for five polyester feeder yarns textured on two texturing machines. The data show that there are important effects on physical properties of varying texturing temperature, but that the extent and type of the effects depends on the feeder yarn-texturing machine combination. For the combinations studied, tenacity, basic elongation, crimp rigidity, crimp elongation, Leesona Skein Shrinkage, and the effective yarn temperature from Kanebo Thermal Stress Analyzer data showed significant dependence on texturing temperature for at least one feeder yarn. Neither denier nor initial modulus was texturing-temperature-dependent for any of these feeder yarns. The data also show that, in those instances where a property is texturing-temperature-dependent for more than one feeder yarn, the magnitude of the dependence ( i.e., the slope of the property versus texturing temperature curve) is similar for all feeder yarns affected. Therefore, these feeder yarns tend to have equal sensitivity to changes in texturing temperature, if they have any sensitivity at all.

Thermomechanical Behavior of Viscoelastic Media With Variable Properties Subjected to Cyclic Loading

1965 ◽  
Vol 32 (3) ◽  
pp. 611-619 ◽  
Author(s):  
R. A. Schapery
Keyword(s):  
Steady State ◽  
Variational Method ◽  
Variational Principles ◽  
Thermomechanical Behavior ◽  
Shear Loading ◽  
Large Temperature ◽  
Temperature Dependent ◽  
Concentrated Mass ◽  
Mass System ◽  
Temperature Dependent Properties

The interaction between heat and dynamic response of viscoelastic bodies with temperature-dependent properties is studied. First, equations governing the small deformation thermomechanical response to sinusoidal loading are shown to be equivalent to a set of two variational principles. Viscoelastic properties of a solid propellant are characterized and then used in numerical examples dealing with sinusoidal shear loading of slabs and cylinders. As the first problem, an approximate variational method is used to calculate one-dimensional transient and steady-state temperature distributions in a massless slab. An exact steady-state solution is obtained for the thermomechanical behavior of a slab with concentrated mass and is then used to deduce the solution for a similarly loaded cylinder. Finally, the influence of distributed mass in a cylinder is studied using a variational method. It is found that without inertia a large temperature rise may occur when the applied stress amplitude is above a certain critical value which depends on thermal and mechanical properties, geometry, and frequency. Moreover, the combination of temperature-dependent properties and inertia leads to temperature and displacement jump instabilities that are similar to those existing in a nonlinear spring-mass system with a spring that softens with increasing displacement.

scholarly journals The temperature dependence of the adrenergic Na+/H+ exchanger of trout erythrocytes

1990 ◽  
Vol 148 (1) ◽  
pp. 303-312 ◽  
Author(s):  
A. R. Cossins ◽  
R. V. Kilbey
Keyword(s):  
Steady State ◽  
Rainbow Trout ◽  
Temperature Dependence ◽  
Effect Of Temperature ◽  
Transport Mechanisms ◽  
Adrenergic Stimulation ◽  
Temperature Dependent ◽  
Effects Of Temperature ◽  
Time Required

The effects of temperature upon the adrenergic Na+/H+ exchange of rainbow trout erythrocytes have been studied in vitro. The initial rates of H+ ejection and of increase of intracellular Na+ [(Na+]i) in adrenergically stimulated cells were highly temperature-dependent, with apparent Arrhenius activation energies of 112.8 +/− 10.0 (mean +/− S.D., N = 4) and 84.1 +/− 3.0 kJ mol-1 (N = 3), respectively. The steady-state [Na+]i following stimulation decreased progressively with cooling, whilst the time required for [Na+]i to return to control values after removal of agonist was greatly increased. The change in intracellular pH resulting from adrenergic stimulation was reduced by cooling, such that at 4 degrees C adrenergic responses were barely measurable. The effect of temperature upon the steady-state [Na+]i and pHi was probably caused by a disparity in the temperature dependence of the transport mechanisms that contribute to the respective steady states.

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