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MECHANICAL STRENGTH OF FRESH BIRCH WOOD FOR WIND RESISTANCE MODELLING
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L.Sisenis; S.Lise; E.Cukurs;R. Kapostins;B. Jansone
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1314-2704
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English
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20
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3.1
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Wind is by far the most important natural disturbance, shaping the forest composition and age structure in Europe. Birch (Betula spp.) is among the wind-resistant species, especially during the season of extra-tropical cyclone storms, when it typically is in leaf-less state. However, predicted shifts in the frequency and seasonality of storms will affect also this species, therefore modelling of its wind resistance is important. For this purpose, among others, data on wood properties are essential. Typically such data are available from wood tests with specific levels of moisture content in wood; however, for the purpose of wind modelling fresh wood parameters are needed. Therefore, the aim of our study was to obtain such parameters.
Samples were collected from 30 trees and tests were carried out in accordance to standards EN 13183-1 and ISO 3131 p.7.1. Samples taken at the stem base, at breast height (1.3 m) and at half of the tree height. Stem wood density was highest at the middle of the tree (499 kg m-3) and decreasing towards its stem base (471 kg m-3). Modulus of rapture (MOR) and modulus of elasticity (MEL) followed the same trend and were 32.1 and 28.0 N mm2, respectively, and 63.3 and 58.6 N mm-2, respectively. Lowest values of all three parameters were observed at the breast height, indicating the adaptation to wind-load close to tree root collar. These figures can be part of the explanation related to wind damage height of birch and will be further used in the modelling of the storm impact to this species. |
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conference
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20th International Multidisciplinary Scientific GeoConference SGEM 2020
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20th International Multidisciplinary Scientific GeoConference SGEM 2020, 18 - 24 August, 2020
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Proceedings Paper
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STEF92 Technology
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International Multidisciplinary Scientific GeoConference-SGEM
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SWS Scholarly Society; Acad Sci Czech Republ; Latvian Acad Sci; Polish Acad Sci; Russian Acad Sci; Serbian Acad Sci & Arts; Natl Acad Sci Ukraine; Natl Acad Sci Armenia; Sci Council Japan; European Acad Sci, Arts & Letters; Acad Fine Arts Zagreb Croatia; C
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701-706
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18 - 24 August, 2020
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website
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cdrom
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7185
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wind resistance; mechanical wood properties; wood density; natural disturbances
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