An Investigation of the Duration of Load of Structural Timber and the Clear Wood
In this study, DOL of structural timber and the clear wood and DOL of modulus of elasticity of wood were investigated. The dimension lumber of Spruce-Pine-Fir of Grade No. 2 and Grade No. 3 and the small clear specimens of the same species of the dimension lumber were used to conduct the short-term...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-08-01
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| Series: | Forests |
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| Online Access: | https://www.mdpi.com/1999-4907/12/9/1148 |
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| author | Qiongyao Wu Liangliang Huo Enchun Zhu Shuang Niu Huajie Wang |
| author_facet | Qiongyao Wu Liangliang Huo Enchun Zhu Shuang Niu Huajie Wang |
| author_sort | Qiongyao Wu |
| collection | DOAJ |
| description | In this study, DOL of structural timber and the clear wood and DOL of modulus of elasticity of wood were investigated. The dimension lumber of Spruce-Pine-Fir of Grade No. 2 and Grade No. 3 and the small clear specimens of the same species of the dimension lumber were used to conduct the short-term and the long-term bending test. The short-term strength distributions of the dimension lumber and the small clear specimens were obtained. The long-term tests were conducted under constant environmental conditions for 18 months. The sample matching technique was used to estimate the short-term strength of the specimens that underwent long-term tests. It was found out that there is virtually no difference in DOL between different grades or quality of lumber and no difference between structural timber and clear wood, and DOL obtained from the test of this study is more in agreement with Wood’s curve. A threshold stress ratio of about 0.55, loaded above which the wood began to experience strength loss, was revealed from the test. Making use of the threshold ratio concept, the DOL of wood can be obtained not only from failed specimens under load in the process of the long-term loading, but also from the ramp loading test of the specimens that survived the long-term test. Sustained load also poses DOL on the modulus of elasticity of wood, though to less degree than DOL of strength of wood. |
| first_indexed | 2024-03-10T07:40:48Z |
| format | Article |
| id | doaj.art-9aa36d86df4446c284657d9574a6b65d |
| institution | Directory Open Access Journal |
| issn | 1999-4907 |
| language | English |
| last_indexed | 2024-03-10T07:40:48Z |
| publishDate | 2021-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Forests |
| spelling | doaj.art-9aa36d86df4446c284657d9574a6b65d2023-11-22T13:06:46ZengMDPI AGForests1999-49072021-08-01129114810.3390/f12091148An Investigation of the Duration of Load of Structural Timber and the Clear WoodQiongyao Wu0Liangliang Huo1Enchun Zhu2Shuang Niu3Huajie Wang4China Construction First Group Construction & Development Co., Ltd., Beijing 100102, ChinaKey Laboratory of Structures Dynamic Behavior and Control of China Ministry of Education, School of Civil Engineering, Harbin Institute of Technology, Harbin 150090, ChinaDepartment of Civil Engineering, Harbin Institute of Technology at Weihai, School of Ocean Engineering, Weihai 264209, ChinaDepartment of Civil Engineering, Harbin Institute of Technology at Weihai, School of Ocean Engineering, Weihai 264209, ChinaDepartment of Civil Engineering, Harbin Institute of Technology at Weihai, School of Ocean Engineering, Weihai 264209, ChinaIn this study, DOL of structural timber and the clear wood and DOL of modulus of elasticity of wood were investigated. The dimension lumber of Spruce-Pine-Fir of Grade No. 2 and Grade No. 3 and the small clear specimens of the same species of the dimension lumber were used to conduct the short-term and the long-term bending test. The short-term strength distributions of the dimension lumber and the small clear specimens were obtained. The long-term tests were conducted under constant environmental conditions for 18 months. The sample matching technique was used to estimate the short-term strength of the specimens that underwent long-term tests. It was found out that there is virtually no difference in DOL between different grades or quality of lumber and no difference between structural timber and clear wood, and DOL obtained from the test of this study is more in agreement with Wood’s curve. A threshold stress ratio of about 0.55, loaded above which the wood began to experience strength loss, was revealed from the test. Making use of the threshold ratio concept, the DOL of wood can be obtained not only from failed specimens under load in the process of the long-term loading, but also from the ramp loading test of the specimens that survived the long-term test. Sustained load also poses DOL on the modulus of elasticity of wood, though to less degree than DOL of strength of wood.https://www.mdpi.com/1999-4907/12/9/1148timberduration of loadlong-term strengthMadison Curvethreshold stress ratio |
| spellingShingle | Qiongyao Wu Liangliang Huo Enchun Zhu Shuang Niu Huajie Wang An Investigation of the Duration of Load of Structural Timber and the Clear Wood Forests timber duration of load long-term strength Madison Curve threshold stress ratio |
| title | An Investigation of the Duration of Load of Structural Timber and the Clear Wood |
| title_full | An Investigation of the Duration of Load of Structural Timber and the Clear Wood |
| title_fullStr | An Investigation of the Duration of Load of Structural Timber and the Clear Wood |
| title_full_unstemmed | An Investigation of the Duration of Load of Structural Timber and the Clear Wood |
| title_short | An Investigation of the Duration of Load of Structural Timber and the Clear Wood |
| title_sort | investigation of the duration of load of structural timber and the clear wood |
| topic | timber duration of load long-term strength Madison Curve threshold stress ratio |
| url | https://www.mdpi.com/1999-4907/12/9/1148 |
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