Address: Naberezhnaya Severnoy Dviny, 17, Arkhangelsk, 163002, Russian Federation, Northern (Arctic) Federal University named after M.V.Lomonosov, office 1425

Phone: +7 (8182) 21-61-18
E-mail: forest@narfu.ru
http://lesnoizhurnal.ru/en/

Lesnoy Zhurnal

Resin Pocket Formation in Tree Stems of Dahurian Larch

Версия для печати

V.N. Glukhikh, A.Yu. Okhlopkova

Complete text of the article:

Download article (pdf, 0.7MB )

UDС

674.038.1

DOI:

10.17238/issn0536-1036.2017.5.35

Abstract

The paper analyzes the study results of native and foreign authors of the strain-stress state and distribution of internal stresses in a tree stem. The cyclic tensile and compressive stresses, arising at the wind load, are superimposed on the initial stresses when their further modifications in the tree growth process. The tree stem as a balanced system and a living organism strives to compensate the arising loads by increasing the density of cell walls and changing their structure – twisting. The occurrence of extreme loads and cyclic rocking loads can cause microdamages – cracks. The cavities of coniferous trees are filled with a natural antiseptic - resin. A further increase of cavities and filling of resin pockets occur under the influence of fluctuating compression and tensile stresses. In accordance with the nature of initial stresses in the radial and tangential directions, the pockets on the average are longer in the zones of the greatest radial tensile stresses. The goal of research is the substantiation of the location of the greatest resin pockets accumulation. Based on the fact that the shape of a trunk corresponds to the shape of a rod of equal resistance, in which the stresses in the outer fibers during bending should be the same over the entire height of the tree, we have calculated the circumferential and radial stresses along the radius of the stem cross section. Taking into account the relationship between the size of the core zone, stresses at the center and along the outline of the section and ultimate strength of wood under static bending and compression, the authors have used the distribution function of the initial longitudinal stress in the form of a paraboloid of the 14th degree to calculate the initial stresses in the Dahurian larch stem by the material resistance methods. As a result, the epure of stem total stress has been obtained. According to the generalized Hooke's law, we have designed a distribution graph of the main relative strain in the radial direction along the diameter of the stem cross section. As a confirmation of the theory of the resin pockets formation, we have conducted the laboratory tests to determine the strength limits when static bending and compression along the fibers, taking into account the ratio of radii of heartwood and sapwood in the samples. The study of the pocket localization along the diameter of the stem cross section of Dahurian larch has proved that the greatest resin pockets accumulation is in the zone of maximum radial deformation.

Authors

V.N. Glukhikh 1, Doctor of Engineering Sciences, Professor
A.Yu. Okhlopkova 2, Wood Process Engineer

Affiliation

1Saint Petersburg State University of Architecture and Civil Engineering,
Vtoraya Krasnoarmeyskaya ul., 4, Saint Petersburg, 190005, Russian Federation; e-mail: vnglukhikh@mail.ru
2Woodworking Complex “Asia Les”, per. Oblachnyi, 78A, off. 11, Khabarovsk, 680030, Russian Federation; e-mail: anna.okhlopkova@gmail.com

Keywords

wood, tree stem, strain-stress state, internal and initial stress, growth stress, resin pocket, Dahurian larch

For citation

Glukhikh V.N., Okhlopkova A.Yu. Resin Pocket Formation in Tree Stems of Dahurian Larch. Lesnoy zhurnal [Forestry journal], 2017, no. 5, pp. 35–52. DOI: 10.17238/issn0536-1036.2017.5.35

References

1. Ashkenazi E.K. Anizotropiya drevesiny i drevesnykh materialov [Anisotropy of Wood and Wood Materials]. Moscow, Lesnaya promyshlennost’ Publ., 1978. 224 p. (In Russ.)
2. Belov S.V. Veter – glavnyy faktor, opredelyayushchiy formu stvolov derev'ev i ikh ustoychivost' [The Wind as the Main Factor Determining the Shape of Tree Stems and Their Stability]. Lesovodstvo, lesnye kul'tury i pochvovedenie [Forestry, Forest Cultures and Soil Science]. Leningrad, 1974, iss. III, pp. 3–24.
3. Glukhikh V.N. K voprosu o napryazheniyakh v stvole dereva iz-za sobstvennogo vesa: [On the Stresses in a Tree Stem Because of Its Own Weight] materialy 5-y mezhdunar. nauch.-prakt. konf. «Lesa Rossii v XXI veke» Proc. 5th Inter. Sci. and Practical Conf. “Forests of Russia in the 21st Century”]. Saint Petersburg, 2010, pp. 5–11. (In Russ.)
4. Glukhikh V.N., Akopyan A.L. Nachal'nye napryazheniya v drevesine: monogr. [Initial Stresses in Wood]. Saint Petersburg, SPSUACE Publ., 2016. 118 p. (In Russ.)
5. Glukhikh V.N., Chernykh A.G. Anizotropiya drevesiny. Tekhnologicheskiy aspekt: monogr. [Anisotropy of Wood. Technological Aspect]. Saint Petersburg, SPSUACE Publ., 2013. 240 p. (In Russ.)
6. GOST 2140–81. Vidimye poroki drevesiny. Klassifikatsiya, terminy i opredeleniya, sposoby izmereniya [State Standard 2140–81. Visible Defects of Wood. Classification, Terms and Definitions, Methods of Measurement]. Moscow, Standartinform Publ., 1981. 118 p.
7. Ivanov L.A. Biologicheskie osnovy dobyvaniya terpentina v SSSR [Biological Basis for the Terpentine Extraction in the USSR]. Moscow; Leningrad, Goslesbumizdat Publ., 1940. 289 p. (In Russ.)
8. Kuznetsov A.I. Vnutrennie napryazheniya v drevesine [Internal Stresses in Wood]. Moscow; Leningrad, Goslesbumizdat Publ., 1950. 59 p. (In Russ.)
9. Leont'ev N.L. Uprugie deformatsii drevesiny [Elastic Deformation of Wood]. Moscow; Leningrad, Goslesbumizdat Publ., 1952. 120 p. (In Russ.)
10. Leont'ev N.L. Vliyanie vlazhnosti na fiziko-mekhanicheskie svoystva drevesiny [The Moisture Effect on the Physical and Mechanical Properties of Wood]. Moscow, Goslesbumizdat Publ., 1962. 114 p. (In Russ.)
11. Lekhnitskiy S.G. Teoriya uprugosti anizotropnogo tela [The Anisotropic Theory of Elasticity]. Moscow, Nauka Publ., 1977. 416 p. (In Russ.)
12. Chakhov D.K., Doktorov I.A., Lavrov M.F., Okhlopkova A.Yu., Semenova S.A. Otsenka kachestva drevesnogo syr'ya khvoynykh porod, proizrastayushchikh v Yakutii: otchet o NIR [Quality Assessment of Wood Raw Materials of Coniferous Species Growing in Yakutia]. Yakutsk, 2011. 116 p. (In Russ.)
13. Crown D.J. Resin Pockets: Their Occurrence and Formation in New Zealand Forests. New Zealand Journal of Forestry, 1973, vol. 18(2), pp. 233-251.
14. K`bler H. Studien-ber Wachstumsspannungen des Holzes - Erste Mitteilung: Die Ursache der Wachstumsspannungen und die Spannungen quer zur Faserrichtung. Holzals Roh - und Werkstoff, 1959, vol. 17, iss. 1, pp. 1–9.
15. Lerm F.J. A Method for Three-Dimensional Stem Analysis and Its Application in a Study on the Occurrence of Resin Pockets in Pinus patula: Master of Science in Forestry (Wood Products Science) Diss. South Africa, Stellenbosch, 2013. 116 p.
16. Temnerud E., Valinger E., Sundberg B. Induction of Resin Pockets in Seedlings of Pinus sylvestris L. by Mechanical Bending Stress During Growth. Holzforschung, 1999, vol. 53, no. 4, pp. 386?390.
17. Ylinen A.-ber die mechanische Schaftformtheorie der B`ume. Silva Fennica, 1952, no. 76. 51 p.
18. Wood C.J. Understanding Wind Forces on Trees. Wind and Trees. Ed. by M.P. Coutts, J. Grace. Cambridge, Cambridge University Press, 1995, pp. 133–164.
Received on March 15, 2017

Resin Pocket Formation in Tree Stems of Dahurian Larch

 

Make a Submission


ADP_cert_2024.png

Lesnoy Zhurnal (Russian Forestry Journal) was awarded the "Seal of Recognition for Active Data Provider of the Year 2024"

INDEXED IN: 


DOAJ_logo-colour.png

logotype.png

Логотип.png