REGULARITIES OF THE INFLUENCE OF ANISOTROPY OF MECHANICAL CHARACTERISTICS ON THE VISCOELASTIC STATE OF THE WOOD

Author:

Sokolovskyy Yaroslav, Ukrainian National Forestry University, Lviv, Ukraine

Kryshtapovych Volodymyr, Ukrainian National Forestry University, Lviv, Ukraine

Kroshnyy Igor, Ukrainian National Forestry University, Lviv, Ukraine

Language: ukrainian

Annotation:

The mathematical model of elastic-visco-plastic deformation of wood is synthesized in the conditions of non-isothermal moisture transfer taking into account the anisotropy of mechanical properties of material and deformations caused by a mechanic-sorption creep. The algorithm of the finite element method is constructed for the realization of models. It allows to investigate the influence of non-stationary fields of heat and mass transfer on the development of elastic, viscoelastic and plastic deformations in wood with consideration of the mechanism of their regeneration. As a result of computational experiments carried out using the developed object-oriented software tools established patterns of influence of anisotropy of thermo-physical and mechanical properties of wood, its initial moisture, geometrical parameters to change of visco-elastic-plastic state of material in the conditions of non-isothermal moisture transfer.

Key words:

mathematical model, finite element method, moisture transfer, the anisotropy of properties, elastic-visco-plastic state, object-oriented programming, wood

References:

1. Beliankin, F.P., Iacenko, V.F. (1957). Deformativnost i soprotivliaemost [Deformability and resistance of wood]. Kiev: АN USSR (in Russian).

2. Gorokhovskii, A.G. (2004). Issledovanie rasbrosa vlazhnosti sukhikh pilomaterialov na kachestvo produktsii derevoobrabotki [Investigation of the dispersion of humidity of dry timber on the quality of wood products].Derevoobrabatyvaiushchaia promyshlennost – Woodworking industry, no. 4, pp. 56–59 (in Russian).

3. Lykov, A.V. (1971). Teplomassoobmen: spravochnik [Heat and mass transfer: reference book]. Moscow: Energia (in Russian).

4. Mozharovskii, N.S., Kochalovskaia, N.Е. (1981). Metody i algoritmy resheniia kraevykh zadach [Methods and algorithms for solving boundary value problems]. Кiev: Vyshcha shkola (in Russian).

5. Pisarenko, G.S., Iakovlev, A.P., Matveev, V.V. (1988). Spravochnik po soprotivleniiu materialov [Handbook on the resistance of materials]. Kiev: Naukova Dumka (in Russian).

6. Pinchevska, O.O., Holovach, V.M., Horbachova, O.Yu. (2014). Vplyv rezhymiv termichnoho modyfikuvannia na fizychni vlastyvosti derevyny hraba [The influence of thermal modification modes on the physical and mechanical properties of hornbeam]. Annals of Warsaw University of Life Sciences – SGGW. Forestry and Wood Technology, no. 88, pp. 193–197 (in Ukrainian).

7. Savin, G.M. (1970). Elementy mekhaniky spadkovykh seredovyshch. Vyp. ІІ: Reologichni tila z zagalnym zakonom linijnogo deformuvannja [Elements of mechanics of hereditary environments. Volume II: Rheological body with universal law of linear deformation]. Kiev (in Ukrainian).

8. Segerlind, L. (1979). Primenenie metoda konechnykh elementov [The application of the finite element method]. Moscow: Mir (in Russian).

9. Sokolovskii, Ya.І., Kroshnii, І.М. (2012). Alhorytmichne ta prohramne zabezpechennia systemy modeliuvannia ta analizu protsesu sushinnia kapiliarno-porystykh materialiv [Algorithmic and software system modeling and analysis of drying of capillary-porous materials]. Visnyk Natsionalnoho universytetu „Lvivska politekhnika”: Kompiuterni nauky ta informatsiini tekhnolohii – Proceedings of the National University “Lviv Polytechnic”, Computer Science and Information Technology. Lviv: Publishing House Lviv Polytechnic, no. 732, pp. 306–315 (in Ukrainian).

10. Sokolovskii, Ya.I., Mokrytska, O.V. (2011). Matematychna model viazkopruzhnoho deformuvannia kapiliarno-porystykh materialiv [Mathematical model of viscoelastic deformation of capillary-porous materials].Naukovyi visnyk Natsionalnoho lisotekhnichnoho universytetu Ukrainy – Scientific Bulletin of National Forestry University of Ukraine. Lviv, Ukraine NLTU, no. 21.2, pp. 320–328 (in Ukrainian).

11. Sokolovskii, Ya.I., Shymanskyi, V.M. (2012). Matematychna model teplovolohoperenesennia ta napruzheno-deformivnoho stanu u kapiliarno-porystykh materialakh iz fraktalnoiu strukturoiu [A mathematical model of heat and moisture transfer and stress-strained state in capillary-porous materials with fractal structure]. Fizyko-matematychne modeliuvannia ta informatsiini tekhnolohii – Physical modeling and information technology. Lviv: Center of Mathematical Modeling Institute of Applied Problems of Mechanics and Mathematics. Pidstryhach NAS of Ukraine, no. 16, pp. 133–142 (in Ukrainian).

12. Sokolovskii, Ya.І., Kroshnyi, І.М. (2011). Matematychne modeliuvannia vplyvu zovnishnoho seredovyshcha na napruzheno-deformivnyi stan derevyny u protsesi sushinnia [Mathematical modeling of the impact of the environment on stress-strain state in the process of drying wood]. Visnyk Natsionalnoho universytetu „Lvivska politekhnika”: Kompiuterni systemy proektuvannia. Teoriia i praktyka – Visnyk of the National University “Lviv Polytechnic”: Computer Systems. Theory and practice. Lviv: Publishing House Lviv Polytechnic, no. 711, pp. 72–82 (in Ukrainian).

13. Sokolovskii, Ya.I., Andrashek, I.V. (1999). Metodyka ta rezultaty experymentalnykh doslidzen reolohichnoi povedinky derevyny [The methodology and results of experimental studies rheological behavior of wood].Naukovyi visnyk UkrDLTU Ukrainy. Lviv, no. 9.13, pp. 15-26 (in Ukrainian).

14. Tiuleneva, E.M. (2004). Eksperimentalnoe opredelenie modulia uprugosti pervogo roda [Experimental determination of the modulus of elasticity of the first kind]. Lesnoi i khimicheskii kompleksy – problemy i resheniia – Forest and chemical complexes – problems and solutions. Krasnoyarsk, part II, pp. 113–114 (in Russian).

15. Ugolev, B.N. (2002). Drevesinovedenie s osnovami lesnogo tovarovedenia [Wood Science with the Basics of Forest Goods Science] (3ed ed.). Moscow: МGUL (in Russian).

16. Shubin, G.S. (1990). Sushka i teplovaia obrabotka drevesiny [Drying and heat treatment of wood]. Moscow: Lesnaia promyshlennost (in Russian).

17. Bodic, J., Jayne, A. (1982). Mechanics of Wood and Composites. New York: Van Nostraind Reinhold.

18. John F. Sian. (1995). Wood: influence of moisture on physical properties. Virginia.

19. Niemz, P., Caduff, D. (2008). Research into determination of the Poisson ratio of spruce wood. Holz Roh Werkst, no. 66(1), pp. 1–4.

20. Perre, P., Passard, J. (2004). A physical and mechanical model able to predict the stress field in wood over a wide range of drying conditions. Drying Technology, vol. 22, no. 1–2, pp. 27–44.

21. Sokolovskii, Ya., Storoshuk, O. (2014). Demention of the Non-isotropic Elastic Features for Wood by an Ultrasonic Method. Proceedings from 57th SWST Convention of Society of Wood Science and Technology(Zvolen, Slovakia), pp. 178–187.

22. Sokolowskii, Ya., Shymanskyi, V. (2014). Mathematical modelling of non-isothermal moisture transfer and rheological behavior in cappilary-porous materials with fractal structure during drying. Computer and Information Science, Canadian Center of Science and Education, vol. 7, no. 4, pp. 111–122.

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