STRESS-STRAIN STATE OF CURVED LAMINATED WOODEN ELEMENTS DURING PRODUCTION
Introduction: The stress-strain state (SSS) of curved laminated wooden elements may differ significantly from the SSS of straight laminated wooden elements, not only in terms of the curvature but also in terms of production specifics and operational load. A curved element is produced by bending wood...
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| Format: | Article |
| Language: | English |
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Saint Petersburg State University of Architecture and Civil Engineering
2020-12-01
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| Series: | Architecture and Engineering |
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| Online Access: | https://aej.spbgasu.ru/index.php/AE/article/view/334/179 |
| _version_ | 1818922972238315520 |
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| author | Alexander Schmidt |
| author_facet | Alexander Schmidt |
| author_sort | Alexander Schmidt |
| collection | DOAJ |
| description | Introduction: The stress-strain state (SSS) of curved laminated wooden elements may differ significantly from the SSS of straight laminated wooden elements, not only in terms of the curvature but also in terms of production specifics and operational load. A curved element is produced by bending wooden planks (lamellae) and gluing them together. In the process, the structure is subjected to initial internal stresses, as the lamellae tend to straighten out again. After production is complete, the element experiences unequal initial internal stresses, which alters its strength properties in different directions in relation to the timber fibers. At a later point, this is going to contribute to the stresses that the structure experiences under external pressure. The Russian and foreign regulations (SP, EuroCode 5, DIN) do not pay sufficient attention to this fact, which has merited this study. Methods: For the aforementioned purpose, we review a mathematical model of the SSS emergence in curved laminated wooden elements. We roughly divide the process into two stages: stage 1 involves bending separate lamellae, gluing them together, and pressing them down; stage 2 involves pressing out the laminated package. This results in prestress, which is a combination of tangential, radial, and shear stresses. Results: Our study results in a visual representation of the total prestress during stages 1 and 2. Such a representation allows for predicting stresses in curved laminated wooden structures under alternating operational loads. Discussion: We highlight the impact of the relaxation of initial stresses, which requires further study. Depending on the direction and amount of operational load, the curved laminated section of a structure may “attempt” to straighten out (i.e. with a decrease in curvature), or may curve even further. This is not properly reflected in the guidelines for wooden structures’ design and needs to be examined further. |
| first_indexed | 2024-12-20T02:02:02Z |
| format | Article |
| id | doaj.art-fe741924deea4b909a1b42ec1eb30e51 |
| institution | Directory Open Access Journal |
| issn | 2500-0055 |
| language | English |
| last_indexed | 2024-12-20T02:02:02Z |
| publishDate | 2020-12-01 |
| publisher | Saint Petersburg State University of Architecture and Civil Engineering |
| record_format | Article |
| series | Architecture and Engineering |
| spelling | doaj.art-fe741924deea4b909a1b42ec1eb30e512022-12-21T19:57:18ZengSaint Petersburg State University of Architecture and Civil EngineeringArchitecture and Engineering2500-00552020-12-0154515910.23968/2500-0055-2020-5-4-51-59STRESS-STRAIN STATE OF CURVED LAMINATED WOODEN ELEMENTS DURING PRODUCTIONAlexander Schmidt0Saint Petersburg State University of Architecture and Civil EngineeringIntroduction: The stress-strain state (SSS) of curved laminated wooden elements may differ significantly from the SSS of straight laminated wooden elements, not only in terms of the curvature but also in terms of production specifics and operational load. A curved element is produced by bending wooden planks (lamellae) and gluing them together. In the process, the structure is subjected to initial internal stresses, as the lamellae tend to straighten out again. After production is complete, the element experiences unequal initial internal stresses, which alters its strength properties in different directions in relation to the timber fibers. At a later point, this is going to contribute to the stresses that the structure experiences under external pressure. The Russian and foreign regulations (SP, EuroCode 5, DIN) do not pay sufficient attention to this fact, which has merited this study. Methods: For the aforementioned purpose, we review a mathematical model of the SSS emergence in curved laminated wooden elements. We roughly divide the process into two stages: stage 1 involves bending separate lamellae, gluing them together, and pressing them down; stage 2 involves pressing out the laminated package. This results in prestress, which is a combination of tangential, radial, and shear stresses. Results: Our study results in a visual representation of the total prestress during stages 1 and 2. Such a representation allows for predicting stresses in curved laminated wooden structures under alternating operational loads. Discussion: We highlight the impact of the relaxation of initial stresses, which requires further study. Depending on the direction and amount of operational load, the curved laminated section of a structure may “attempt” to straighten out (i.e. with a decrease in curvature), or may curve even further. This is not properly reflected in the guidelines for wooden structures’ design and needs to be examined further.https://aej.spbgasu.ru/index.php/AE/article/view/334/179production of curved wooden structuresinitial prestresscurved laminated wooden elementcombination of initial prestress and operational stresses. |
| spellingShingle | Alexander Schmidt STRESS-STRAIN STATE OF CURVED LAMINATED WOODEN ELEMENTS DURING PRODUCTION Architecture and Engineering production of curved wooden structures initial prestress curved laminated wooden element combination of initial prestress and operational stresses. |
| title | STRESS-STRAIN STATE OF CURVED LAMINATED WOODEN ELEMENTS DURING PRODUCTION |
| title_full | STRESS-STRAIN STATE OF CURVED LAMINATED WOODEN ELEMENTS DURING PRODUCTION |
| title_fullStr | STRESS-STRAIN STATE OF CURVED LAMINATED WOODEN ELEMENTS DURING PRODUCTION |
| title_full_unstemmed | STRESS-STRAIN STATE OF CURVED LAMINATED WOODEN ELEMENTS DURING PRODUCTION |
| title_short | STRESS-STRAIN STATE OF CURVED LAMINATED WOODEN ELEMENTS DURING PRODUCTION |
| title_sort | stress strain state of curved laminated wooden elements during production |
| topic | production of curved wooden structures initial prestress curved laminated wooden element combination of initial prestress and operational stresses. |
| url | https://aej.spbgasu.ru/index.php/AE/article/view/334/179 |
| work_keys_str_mv | AT alexanderschmidt stressstrainstateofcurvedlaminatedwoodenelementsduringproduction |