Pt-I. Theoretical Aspects - Internal Friction of Glass.

JSGT 1953 V37 T007-T026

Relationships between internal friction or damping capacity and delayed elastic effects are discussed, both effects being related to a quantity denoting the relaxation ratio of an anelastic process. The connection between damping factors for oscillatory and aperiodic stress–time phenomena is considered. Suggestions are made concerning the probable relationships between the relaxation ratios (and hence internal friction peaks in the acoustic spectrum) corresponding to different types of elastic deformation. The physical causes of anelasticity in glass are considered, including the effects of inhomogeneity, thermal diffusivity, ionic mobility and effective configuration temperature, the result of which is to suggest reasons for the surprisingly small difference in the time order of elastic after-effects at room temperature and those in the transformation range

P. L. Kirby