Justification of application of nonlinear viscoelasticity model of Rabotnov's model type in creep problems
DOI:
https://doi.org/10.17721/1812-5409.2021/3.21Keywords:
nonlinear visco-elasticity, complex stressed state, longitudinal creep, shearing creep, volume creep, diagrams of instant deformation, diagrams of torsion, heredity nuclei, isochronous diagramsAbstract
The relationship between the components of the strain tensor, stress tensor and time is given by the defining equations of the hereditary type, which are written based on the hypothesis of proportionality of the deviators. Thin-walled tubular low-pressure polyethylene elements are considered as the object of research. The scope of the model is substantiated based on the hypothesis of the existence of a single diagram of instantaneous deformation and a single diagram of long-term deformation. The invariance of the tensile and torsion diagrams with respect to the stress state is checked. The region of nonlinear elastic deformation is determined. The defining equations of the model contain a set of functions and coefficients determined from the basic experiments. A method for determining the parameters of heredity kernels of nonlinear viscoelastic materials under complex stress state has been developed. The nonlinearity of viscoelastic properties is given by equations of the Rabotnov's model type. The method is based on the relations between the creep kernels obtained under conditions of complex stress state and the creep kernels under one-dimensional stress state. The method is tested experimentally on the problems of calculating creep deformations under combined loading of thin-walled tubular elements made of low-pressure polyethylene.
Pages of the article in the issue: 111 - 114
Language of the article: Ukrainian
References
RABOTNOV U.N. (1966) Polzuchest` elementov konstrukcii. Moskva: Nauka.
KRISTENSEN R.M. (1974). Vvedenie v teoriu vyazkouprugosti. Moskva: Mir.
GOLUB V.P. KOBZAR U.M. RAGULINA V.S. (2013). K zadache opredeleniya parametrov yader nasledstvennosri izotropnih nelineyno-vyazkouprugih materialov pri slognom napryagennom sostoyanii // Teoret. i prikl. mehanika. - №5(51). – p. 26-35.
GOLUB V.P. KOBZAR U.M. FERNATI P.V. (2014). K resheniu zadach polzuchesti izotropnih nelineyno-vyazkouprugih materialov pri slognom napryagennom sostoyanii // Teoret. i prikl. mehanika. - №5(51). – p. 26-35.
Downloads
Published
How to Cite
Issue
Section
License
Authors who publish with this journal agree to the following terms:
- Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
- Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).