On the problem of calculating shear deformations in prismatic bars made of polymer materials under tension with torsion

Authors

  • V. S. Reznik S.P. Timoshenko Institute of Mechanics NAS Ukraine, 03057, Kyiv, 3 Nesterov Str.
  • O. V. Ushakov Ukrainian scientific and research Institute of special equipment and forensic expertise of the Security Service of Ukraine. 03113 Vasilenko str 5, Kyiv
  • O. Y. Gorun Ukrainian scientific and research Institute of special equipment and forensic expertise of the Security Service of Ukraine. 03113 Vasilenko str 5, Kyiv

DOI:

https://doi.org/10.17721/1812-5409.2021/3.22

Keywords:

linear viscosity, longitudinal creep, shear creep, volume creep, heredity nuclei, isochronous diagrams, quantile of statistics

Abstract

The process of creep of prismatic rods made of linear-viscoelastic polymeric materials under combined loading is considered. Defining equations that determine the relationship between strains, stresses and time are given in the form of a superposition of shear and bulk strain. The object of study is prismatic bars made of fiberglass ST-1. The area of linearity of the model is substantiated on the basis of the hypothesis of the existence of the creep function, which is built on the yield curves, a single diagram of long-term deformation and the statistical value of the quantile of statistics. The region of linear-elastic deformation is recognized based on the fulfillment of the condition of existence of a single creep function. The defining equations of the model contain a set of functions and coefficients determined from the basic experiments. On the basis of the relations between the kernels of the one-dimensional stress state, the parameters of the kernels under the condition of a complex stress state are determined. The linearity of viscoelastic properties is given by the Boltzmann-Voltaire equations. The fractional-exponential kernels of heredity are chosen as the kernels of heredity. The obtained values of the core parameters are used to calculate the creep deformations of prismatic bars made of ST-1 fiberglass under conditions of simultaneous tensile tension.

Pages of the article in the issue: 115 - 118

Language of the article: Ukrainian

References

RABOTNOV, Yu. (1966) Polzuchest` elementov konstrukciy. Moskva: Nauka.

KRISTENSEN, R. (1974) Vvedenie v teoriyu vyazkouprugosty. Moskva: Mir.

GOLUB, V., KOBZAR, YU. & RAGULINA, V. (2013) K zadache opredeleniya parametrov yader nasledstvennosti izotropnyh nelinejno-vyazkouprugih materialov pri slozhnom napryazhennom sostoyanii. Teoret. i prikl. mekhanika. 5(51). p. 26-35.

GOLUB, V., KOBZAR, YU. & FERNATI P. K resheniyu zadach polzuchesti izotropnyh nelineino-vyazkouprugih materiaalov pri slozhnom napryazhennom sostoyanii. Teoret. i prikl. mekhanika. 8 (54). P. 45-56.

Downloads

Published

2021-12-07

How to Cite

Reznik, V. S., Ushakov, O. V., & Gorun, O. Y. (2021). On the problem of calculating shear deformations in prismatic bars made of polymer materials under tension with torsion. Bulletin of Taras Shevchenko National University of Kyiv. Physical and Mathematical Sciences, (3), 115–118. https://doi.org/10.17721/1812-5409.2021/3.22

Issue

Section

Differential equations, mathematical physics and mechanics