Elastic Constants of Disordered Solids. II: Temperature Dependence
作者:
Elisabeth Papazoglou,
Robert Simha,
期刊:
Journal of Rheology
(AIP Available online 1987)
卷期:
Volume 31,
issue 2
页码: 135-150
ISSN:0148-6055
年代: 1987
DOI:10.1122/1.549920
出版商: The Society of Rheology
数据来源: AIP
摘要:
We consider the extension of the preceding theory to finite temperatures, while retaining the previous assumptions of affine deformation, of a linear elastic range, and of central interparticle forces. At sufficiently low temperatures, a quasi‐harmonic approximation with volume and strain dependent frequencies ensues. It accounts for an initial linear increase of the Poisson constant μ and a similar decrease of Young's modulusYwith increasing temperature. Numerical evaluation of the complete cell potential and of the free‐volume integral shows that this is followed by plateau regions for both functions, whereas the bulk modulus is but weakly dependent on temperature over the same range of temperatures. This includes a third region of more rapidly decreasingYand increasing μ. However, these latter results require further examination. For upon a further increase in temperature, the validity of the model breaks down, when it would predict a reversal in the sign of the temperature coefficient ofYand impermissible values for μ. This is qualitatively similar to the performance of the cell theory in predicting the thermal expansivity of glasses at low temperatures. Examination of experimental results for some inorganic and organic glasses indicates the existence of the three regions referred to above, or at least the last two.
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