Comparison and Analysis of Radial and Tangential Bending of Softwood and Hardwood at Static and Dynamic Loading
This paper should primarily lead to a targeted expansion of the database dealing with bending characteristics, and thus help to understand the static and dynamic bending strength depending on the direction of external forces. Wood is very often used in the structural elements of buildings and wood p...
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-08-01
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| Series: | Forests |
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| Online Access: | https://www.mdpi.com/1999-4907/11/8/896 |
| _version_ | 1797557283605970944 |
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| author | Vlastimil Borůvka David Novák Přemysl Šedivka |
| author_facet | Vlastimil Borůvka David Novák Přemysl Šedivka |
| author_sort | Vlastimil Borůvka |
| collection | DOAJ |
| description | This paper should primarily lead to a targeted expansion of the database dealing with bending characteristics, and thus help to understand the static and dynamic bending strength depending on the direction of external forces. Wood is very often used in the structural elements of buildings and wood products (e.g., furniture), in which there is both a static load, and in many cases a dynamic load, whilst the direction of loading is usually not considered. Specifically, the paper focuses on determining the bending strength and impact strength of seven economically-important wood species in the Czech Republic. The research includes not only the above-mentioned strength characteristics, but also the elastic characteristics, i.e., the static modulus of elasticity, and the dynamic modules of elasticity determined using the ultrasound and resonance methods. The procedure was methodologically in accordance with the valid harmonized standards or the usual methodological regulations. The most significant finding can be considered that the largest difference of the mean values of impact strength in the radial direction to the tangential direction was recorded for spruce wood, namely 50.3%. Slightly smaller differences were observed for larch wood, i.e., 41.2%. Minor differences of around 20% were recorded for beech, ash and oak wood. A difference with the opposite trend was recorded for birch wood rather than for the above-mentioned woods, namely −9.5%. Linden wood showed almost no difference (−0.8%). With regard to static bending strength, it was found that the largest difference (radial/tangential) was recorded for oak wood, i.e., 7.9%, while smaller differences were found for linden wood amounting to 6.6% and birch 4.7%. For spruce, larch, beech and ash wood, these differences are negligible. Another finding is that the dynamic modules of elasticity are greatly overestimated compared to static modules of elasticity. In the case of the examined wood of coniferous trees, these differences were up to a maximum of 20%. For wood of wood species with a diffuse-porous structure of wood, the differences were more pronounced, i.e., the range of 36% to 68%, and for wood species with a ring-porous structure in the range of 21% to 43%. |
| first_indexed | 2024-03-10T17:14:57Z |
| format | Article |
| id | doaj.art-29846830ed8b4e7e80c3543c711cca80 |
| institution | Directory Open Access Journal |
| issn | 1999-4907 |
| language | English |
| last_indexed | 2024-03-10T17:14:57Z |
| publishDate | 2020-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Forests |
| spelling | doaj.art-29846830ed8b4e7e80c3543c711cca802023-11-20T10:32:25ZengMDPI AGForests1999-49072020-08-0111889610.3390/f11080896Comparison and Analysis of Radial and Tangential Bending of Softwood and Hardwood at Static and Dynamic LoadingVlastimil Borůvka0David Novák1Přemysl Šedivka2Department of Wood Processing and Biomaterials, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, 16500 Prague, Czech RepublicDepartment of Wood Processing and Biomaterials, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, 16500 Prague, Czech RepublicDepartment of Wood Processing and Biomaterials, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, 16500 Prague, Czech RepublicThis paper should primarily lead to a targeted expansion of the database dealing with bending characteristics, and thus help to understand the static and dynamic bending strength depending on the direction of external forces. Wood is very often used in the structural elements of buildings and wood products (e.g., furniture), in which there is both a static load, and in many cases a dynamic load, whilst the direction of loading is usually not considered. Specifically, the paper focuses on determining the bending strength and impact strength of seven economically-important wood species in the Czech Republic. The research includes not only the above-mentioned strength characteristics, but also the elastic characteristics, i.e., the static modulus of elasticity, and the dynamic modules of elasticity determined using the ultrasound and resonance methods. The procedure was methodologically in accordance with the valid harmonized standards or the usual methodological regulations. The most significant finding can be considered that the largest difference of the mean values of impact strength in the radial direction to the tangential direction was recorded for spruce wood, namely 50.3%. Slightly smaller differences were observed for larch wood, i.e., 41.2%. Minor differences of around 20% were recorded for beech, ash and oak wood. A difference with the opposite trend was recorded for birch wood rather than for the above-mentioned woods, namely −9.5%. Linden wood showed almost no difference (−0.8%). With regard to static bending strength, it was found that the largest difference (radial/tangential) was recorded for oak wood, i.e., 7.9%, while smaller differences were found for linden wood amounting to 6.6% and birch 4.7%. For spruce, larch, beech and ash wood, these differences are negligible. Another finding is that the dynamic modules of elasticity are greatly overestimated compared to static modules of elasticity. In the case of the examined wood of coniferous trees, these differences were up to a maximum of 20%. For wood of wood species with a diffuse-porous structure of wood, the differences were more pronounced, i.e., the range of 36% to 68%, and for wood species with a ring-porous structure in the range of 21% to 43%.https://www.mdpi.com/1999-4907/11/8/896woodbending strengthimpact bending strengthmodulus of elasticitydensityultrasound |
| spellingShingle | Vlastimil Borůvka David Novák Přemysl Šedivka Comparison and Analysis of Radial and Tangential Bending of Softwood and Hardwood at Static and Dynamic Loading Forests wood bending strength impact bending strength modulus of elasticity density ultrasound |
| title | Comparison and Analysis of Radial and Tangential Bending of Softwood and Hardwood at Static and Dynamic Loading |
| title_full | Comparison and Analysis of Radial and Tangential Bending of Softwood and Hardwood at Static and Dynamic Loading |
| title_fullStr | Comparison and Analysis of Radial and Tangential Bending of Softwood and Hardwood at Static and Dynamic Loading |
| title_full_unstemmed | Comparison and Analysis of Radial and Tangential Bending of Softwood and Hardwood at Static and Dynamic Loading |
| title_short | Comparison and Analysis of Radial and Tangential Bending of Softwood and Hardwood at Static and Dynamic Loading |
| title_sort | comparison and analysis of radial and tangential bending of softwood and hardwood at static and dynamic loading |
| topic | wood bending strength impact bending strength modulus of elasticity density ultrasound |
| url | https://www.mdpi.com/1999-4907/11/8/896 |
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