Wpływ napromieniowania i temperatury na właściwości reologiczne polietylenu

The paper presents the evaluation of the state equation of the viscoelastic material using creep test as a basis. The state equation has the form of a linear differential equation of the third order. This is proved to be sufficient to simulate the behaviour of the material in the basic creep test as well as in the test of deformation at the constant strain rate which served as a verification. In order to simplify the calculations, mechanical models of viscoelasticity have been applied. All tests were performed on Polish polyethylene ``Politen'' II-OO3/GO/OO, which underwent the creep tests in various temperatures and after being irradiated with various doses. The optimal irradiation dose was found, which, for this kind of material, is 90x10^4 J/kg.