Steady-State Melting of a Semi-Infinite Medium with Temperature-Dependent Properties

1960 ◽  
Vol 27 (6) ◽  
pp. 470-472 ◽  
Author(s):  
Stephen J. Citron
Keyword(s):  
Steady State ◽  
Infinite Medium ◽  
Temperature Dependent ◽  
Temperature Dependent Properties

Transient Thermoelastic Problem for an Infinite Medium With a Spherical Cavity Exhibiting Temperature-Dependent Properties

1962 ◽  
Vol 29 (2) ◽  
pp. 399-407 ◽  
Author(s):  
Jerzy Nowinski
Keyword(s):  
Thermal Expansion ◽  
Shear Modulus ◽  
Perturbation Method ◽  
Temperature Rise ◽  
Spherical Cavity ◽  
Infinite Medium ◽  
Thermoelastic Problem ◽  
Linear Variation ◽  
Temperature Dependent ◽  
Temperature Dependent Properties

This paper is concerned with a polarly symmetric transient thermoelastic problem for an infinite medium with a spherical cavity, the boundary of the cavity being subjected to a sudden temperature rise. Thermal and elastic properties of the medium are assumed to be temperature dependent. Using the perturbation method general equations for the displacements and stresses corresponding to particular boundary-value problems have been found. An illustrative example, involving linear variation of conductivity and thermal expansion as well as quadratic variation of shear modulus with temperature, has been discussed in detail.

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.

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 Temperature-Dependent Properties of Molten Li2BeF4 Salt Using Ab Initio Molecular Dynamics

ACS Omega ◽  
2021 ◽  
Author(s):  
Khagendra Baral ◽  
Saro San ◽  
Ridwan Sakidja ◽  
Adrien Couet ◽  
Kumar Sridharan ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
Ab Initio Molecular Dynamics ◽  
Temperature Dependent ◽  
Temperature Dependent Properties

Crystal structure and temperature-dependent properties of Na2H4Ga2GeO8 – a novel gallogermanate

2020 ◽  
Vol 75 (9-10) ◽  
pp. 805-813
Author(s):  
Irma Peschke ◽  
Lars Robben ◽  
Christof Köhler ◽  
Thomas Frauenheim ◽  
Josef-Christian Buhl ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Decomposition Temperature ◽  
Spectroscopic Techniques ◽  
Charge Balance ◽  
Temperature Dependent ◽  
Raman Spectroscopic ◽  
Debye Temperatures ◽  
Diffraction Lattice ◽  
Temperature Dependent Properties ◽  
Balance Structure

AbstractSynthesis, crystal structure and temperature-dependent behavior of Na2H4Ga2GeO8 are reported. This novel gallogermanate crystallizes in space group I41/acd with room-temperature powder diffraction lattice parameters of a = 1298.05(1) pm and c = 870.66(1) pm. The structure consists of MO4 (M = Ga, Ge) tetrahedra in four-ring chains, which are connected by two different (left- and right-handed) helical chains of NaO6 octahedra. Protons coordinating the oxygen atoms of the GaO4 tetrahedra not linked to germanium atoms ensure the charge balance. Structure solution and refinement are based on single crystal X-ray diffraction measurements. Proton positions are estimated using a combined approach of DFT calculations and NMR, FTIR and Raman spectroscopic techniques. The thermal expansion was examined in the range between T = 20(2) K and the compound’s decomposition temperature at 568(5) K, in which no phase transition could be observed, and Debye temperatures of 266(11) and 1566(65) K were determined for the volume expansion.

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