Advances in Engineering Advances in Engineering features breaking research judged by Advances in Engineering advisory team to be of key importance in the Engineering field. Papers are selected from over 10,000 published each week from most peer reviewed journals.
Acta Mechanica ,June 2012, Volume 223, Issue 6, pp 1261-1284
Valeriy Pavlovich Matveenko, Oleg Yurievich Smetannikov, Nikolay Alexandrovich Trufanov, Igor Nikolaevich Shardakov…show all 4hide
Institute of Continuum Media Mechanics, Russian Academy of Sciences, Ac. Korolyeva, 1, 614013 Perm, Russia
Abstract
The phenomenological models of the thermomechanical behavior of polymeric materials in a temperature range including the relaxation transition from the highly elastic to the glassy state (vitrification) and the reverse transition (softening) are considered. A model based on the interpretation of the glass transition as a process of gradual increase in intermolecular bonds in the polymer network, “freezing” the current strain with decreasing temperature is developed. A scalar parameter is introduced—the “degree of vitrification,” to establish the quantitative dependence of the relaxation transition completion by temperature. Constitutive relations of thermomechanical behavior of vitrifying polymers in uniaxial and complicated stress states in the “elastic approximation” simplification are obtained. A system of experiments for the identification of the proposed model material functions and constants is formulated and implemented. Analytical model problems are solved, clearly illustrating the mechanism for generation of technological and residual stresses in glass polymers in non-uniform cooling.
