US EPA

8721905 

Journal Article 

Generalized model of viscoelastic deformation 

Aleksandrov, A; Lekova, S; Milenova, M 

2012 

81 

4 

635-646 

English 

In this paper we consider generalized mathematical model describing the process of viscoelastic deformation of polymer materials. It describes the polyethylene creep under diffusion of liquid environment not interacting chemically with the polymer. We analyse here some results of certain tests produced with samples which have reached beforehand different levels of saturation with cyclohexan and have been afterwards put under mechanical testing of a short creep in pure torsion and uniform loading. Analyzing the results we use the method of orthogonal expansions and at the same time extend it for a process with integrating properties (without self-settling). In this case it is necessary to separate the integral component, which is presented as signal-dependent. 2012 Academic Publications, Ltd.