On some method of the heredity kernel parameters determination of nonlinear viscoelastic materials under the complex stress state

Reznik, V. S. (2019). On some method of the heredity kernel parameters determination of nonlinear viscoelastic materials under the complex stress state. Bulletin of Taras Shevchenko National University of Kyiv. Physics and Mathematics(1), 178–181. https://doi.org/10.17721/1812-5409.2019/1.41

The deformation of viscoelastic medium given by means of constitutive equations of the hereditary type. These equations establish the relationship between the components of strain tensor, the components of stress tensor and the integral time operator, and contain the set of function and coefficients that are determined from the basic experiments. ? method of the heredity kernel parameters determination of nonlinear viscoelastic materials is developed. As the visco-elastic model, the constitutive equations of the hereditary type are chosen in which the relationship between the components of the strain tensor and the stress tensor is given based on the hypothesis of the deviators proportionality. The nonlinearity of the viscoelastic properties is given by the equations of Ratotnov’s type. The method is based on the relations between the creep kernels under complex stress state and the creep kernels under one-dimensional stress state. The method verified experimentally for the problems of determination of creep deformations under combined loading applied to the thin-walled tubular elements made of polyethylene of high density.Key words: nonlinear visco-elasticity, complex stressed state, longitudinal creep, shearing creep, volume creep.Pages of the article in the issue: 178-181Language of the article: Ukrainian