Doppo Matsubara, Y. Wakashima, Yasushi Fujisawa, H. Shimizu, A. Kitamori, K. Ishikawa
A method for calculating plastic clamp force from tightening torque was presented by considering a bi-linear model obtained from experimental tightening torque-clamp force relationships. The practical applicability of the calculation method was verified by tightening tests of (cid:9479)(cid:9526)(cid:9533)(cid:9524)(cid:9528)(cid:9523)(cid:9521)(cid:9513)(cid:9526)(cid:9517)(cid:9509)(cid:9444)(cid:9518)(cid:9509)(cid:9524)(cid:9523)(cid:9522)(cid:9517)(cid:9511)(cid:9509)−bolted joints using metal washers of various sizes. Results were as follows : It was found that a ratio of side-length （diameter） to thickness of metal washers ranging from 7.8 to 16.0 did not affect the torque coefficient. In addition, the ratio of maximum plastic torque coefficient to maximum elastic torque coefficient, γ max and the ratio of minimum plastic torque coefficient to minimum elastic torque coefficient, γ min , which are elements of the calculation method, tended to increase depending on embedment into timber of metal washers in side-length （diameter） to thickness ratios of 10.0 （washer size : 32×t 3.2 mm）, 10.9 （washer size : 35×t
{"title":"Tightening Torque Calculation Method for Plastic Clamp Force of Bolted Timber Joints","authors":"Doppo Matsubara, Y. Wakashima, Yasushi Fujisawa, H. Shimizu, A. Kitamori, K. Ishikawa","doi":"10.2488/JWRS.63.162","DOIUrl":"https://doi.org/10.2488/JWRS.63.162","url":null,"abstract":"A method for calculating plastic clamp force from tightening torque was presented by considering a bi-linear model obtained from experimental tightening torque-clamp force relationships. The practical applicability of the calculation method was verified by tightening tests of (cid:9479)(cid:9526)(cid:9533)(cid:9524)(cid:9528)(cid:9523)(cid:9521)(cid:9513)(cid:9526)(cid:9517)(cid:9509)(cid:9444)(cid:9518)(cid:9509)(cid:9524)(cid:9523)(cid:9522)(cid:9517)(cid:9511)(cid:9509)−bolted joints using metal washers of various sizes. Results were as follows : It was found that a ratio of side-length （diameter） to thickness of metal washers ranging from 7.8 to 16.0 did not affect the torque coefficient. In addition, the ratio of maximum plastic torque coefficient to maximum elastic torque coefficient, γ max and the ratio of minimum plastic torque coefficient to minimum elastic torque coefficient, γ min , which are elements of the calculation method, tended to increase depending on embedment into timber of metal washers in side-length （diameter） to thickness ratios of 10.0 （washer size : 32×t 3.2 mm）, 10.9 （washer size : 35×t","PeriodicalId":17248,"journal":{"name":"Journal of the Japan Wood Research Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74368282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Korai, Ken Watanabe, K. Nakao, Tomoyuki Hayashi
The Relationship between exposure time and modulus of rupture （MOR） of particleboard subjected to outdoor exposure was examined using simple regression analysis or a generalized linear model （GLM）. As for simple regression analysis, it suggested yields of negative values for predicted mean MOR and lower 95% prediction interval when the exposure time is extended, because of an assumption of linearity and homogeneity of normal distribution. By contrast, for GLM, the predicted mean MOR exponentially decreased, approaching zero. The lower 95% prediction interval did not yield any negative values. The GLM analyzed the relationship between the exposure time and MOR, and the effects of the exposure time on the reduction of MOR were evaluated suitably using the GLM. : outdoor exposure, particleboard, generalized linear model, simple regression analysis, 95% prediction interval.
{"title":"Analysis of the Modulus of Rupture of Particleboard Subjected to Outdoor Exposure Using a Generalized Linear Mode","authors":"H. Korai, Ken Watanabe, K. Nakao, Tomoyuki Hayashi","doi":"10.2488/JWRS.63.277","DOIUrl":"https://doi.org/10.2488/JWRS.63.277","url":null,"abstract":"The Relationship between exposure time and modulus of rupture （MOR） of particleboard subjected to outdoor exposure was examined using simple regression analysis or a generalized linear model （GLM）. As for simple regression analysis, it suggested yields of negative values for predicted mean MOR and lower 95% prediction interval when the exposure time is extended, because of an assumption of linearity and homogeneity of normal distribution. By contrast, for GLM, the predicted mean MOR exponentially decreased, approaching zero. The lower 95% prediction interval did not yield any negative values. The GLM analyzed the relationship between the exposure time and MOR, and the effects of the exposure time on the reduction of MOR were evaluated suitably using the GLM. : outdoor exposure, particleboard, generalized linear model, simple regression analysis, 95% prediction interval.","PeriodicalId":17248,"journal":{"name":"Journal of the Japan Wood Research Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90050964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Taku Okuda, T. Nakagawa, Tomoya Murano, Y. Miyoshi, Hirohito Kamei, Takao Sasaki, Yasuhiro Saigusa, Yoshiyuki Wada, Syunji Minato, S. Sakai, Taizou Chiri, N. Fujimoto, Kuniyoshi Shimizu
To investigate the quantitative change of terpenes in sugi (Cryptomeria japonica) board caused by moderate-temperature drying treatments, extracts of sugi board dried by vacuum, conventional kiln, electric heat and air were analyzed by gas chromatograph/mass spectrometer (GC/MS). Extract samples were prepared at 0-1, 1-2 and 17-18 mm from the surface of dried boards using a planer. The results were as follows. Total content of the extracts detected by GC/MS was less in vacuum-dried board than in air-dried board at all three surface depths. Content of sesquiterpene hydrocarbon at 0-1, 1-2 and 17-18 mm from the surface of vacuum-dried board, at 0-1 and 1-2 mm from the surface of conventional kiln-dried board and at 0-1 mm from the surface of electric heat-dried board was less than in air-dried board. Content of oxygenated sesquiterpene at 0-1 mm from the surface of vacuum-dried board and at 0-1 mm from the surface of conventional kiln-dried board was less than in air-dried board. Content of diterpene hydrocarbon: there were no significant differences between drying treatments. Content of oxygenated diterpene at 17-18 mm from the surface of electric heat-dried board was less than in air-dried board. In conclusion, we showed that a portion of terpenes in sugi board exposed to
{"title":"Effect of Heat Drying Treatment on Extracts of Sugi ( Cryptomeria japonica ) Board: Quantitative change of terpenes by moderate-temperature drying treatments@@@中温乾燥によるテルペン類の量的変化","authors":"Taku Okuda, T. Nakagawa, Tomoya Murano, Y. Miyoshi, Hirohito Kamei, Takao Sasaki, Yasuhiro Saigusa, Yoshiyuki Wada, Syunji Minato, S. Sakai, Taizou Chiri, N. Fujimoto, Kuniyoshi Shimizu","doi":"10.2488/JWRS.63.204","DOIUrl":"https://doi.org/10.2488/JWRS.63.204","url":null,"abstract":"To investigate the quantitative change of terpenes in sugi (Cryptomeria japonica) board caused by moderate-temperature drying treatments, extracts of sugi board dried by vacuum, conventional kiln, electric heat and air were analyzed by gas chromatograph/mass spectrometer (GC/MS). Extract samples were prepared at 0-1, 1-2 and 17-18 mm from the surface of dried boards using a planer. The results were as follows. Total content of the extracts detected by GC/MS was less in vacuum-dried board than in air-dried board at all three surface depths. Content of sesquiterpene hydrocarbon at 0-1, 1-2 and 17-18 mm from the surface of vacuum-dried board, at 0-1 and 1-2 mm from the surface of conventional kiln-dried board and at 0-1 mm from the surface of electric heat-dried board was less than in air-dried board. Content of oxygenated sesquiterpene at 0-1 mm from the surface of vacuum-dried board and at 0-1 mm from the surface of conventional kiln-dried board was less than in air-dried board. Content of diterpene hydrocarbon: there were no significant differences between drying treatments. Content of oxygenated diterpene at 17-18 mm from the surface of electric heat-dried board was less than in air-dried board. In conclusion, we showed that a portion of terpenes in sugi board exposed to","PeriodicalId":17248,"journal":{"name":"Journal of the Japan Wood Research Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80030488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"木質壁面パネルが観察者の眼球停留関連電位、眼球運動、 および視覚印象に及ぼす影響","authors":"美音 吉田, 匡司 仲村, 由衣 菊地","doi":"10.2488/JWRS.62.275","DOIUrl":"https://doi.org/10.2488/JWRS.62.275","url":null,"abstract":"","PeriodicalId":17248,"journal":{"name":"Journal of the Japan Wood Research Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73485504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Matsuo, Hiroyuki Yamamoto, K. Umemura, S. Kawai
Color changes of wood during natural aging are important from the aesthetical point of view and as criteria of degradation. The color properties of aged keyaki wood samples were compared with those of recent wood samples and those of heat treated wood samples in the previous paper. The values of L and b of aged wood were lower than those of recent wood, which was similar to those of heat treated wood. The values of a of aged wood were larger than those of recent wood and heat treated wood, showing a different trend compared to heat treated wood. The results of kinetic analysis showed that the color changes during natural aging occurred more rapidly than the prediction estimated from the color changes of heat treated wood. These results were different from those of hinoki wood, which suggested that the responses to natural aging would differ depending on wood species.
{"title":"Color Changes of Wood during Natural Aging and Heat Treatment","authors":"M. Matsuo, Hiroyuki Yamamoto, K. Umemura, S. Kawai","doi":"10.2488/JWRS.62.266","DOIUrl":"https://doi.org/10.2488/JWRS.62.266","url":null,"abstract":"Color changes of wood during natural aging are important from the aesthetical point of view and as criteria of degradation. The color properties of aged keyaki wood samples were compared with those of recent wood samples and those of heat treated wood samples in the previous paper. The values of L and b of aged wood were lower than those of recent wood, which was similar to those of heat treated wood. The values of a of aged wood were larger than those of recent wood and heat treated wood, showing a different trend compared to heat treated wood. The results of kinetic analysis showed that the color changes during natural aging occurred more rapidly than the prediction estimated from the color changes of heat treated wood. These results were different from those of hinoki wood, which suggested that the responses to natural aging would differ depending on wood species.","PeriodicalId":17248,"journal":{"name":"Journal of the Japan Wood Research Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72820121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"希少な天然秋田スギ\"アオヤジロ\"の材質特性","authors":"博 佐藤, 栄 澁谷, 克彦 高田","doi":"10.2488/jwrs.62.153","DOIUrl":"https://doi.org/10.2488/jwrs.62.153","url":null,"abstract":"","PeriodicalId":17248,"journal":{"name":"Journal of the Japan Wood Research Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86568416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"木材－ボルト接合における座金のめり込み挙動解析（第1報）","authors":"独歩 松原, 勝廣 島田, 卓郎 平井, 良 船田, 順昭 服部","doi":"10.2488/JWRS.62.119","DOIUrl":"https://doi.org/10.2488/JWRS.62.119","url":null,"abstract":"","PeriodicalId":17248,"journal":{"name":"Journal of the Japan Wood Research Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90270466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"成長に伴うモウソウチク（Phyllostachys pubescens）の物性発現機構（第1報）","authors":"智明 桐生, 由華 三好, 裕三 古田","doi":"10.2488/JWRS.62.61","DOIUrl":"https://doi.org/10.2488/JWRS.62.61","url":null,"abstract":"","PeriodicalId":17248,"journal":{"name":"Journal of the Japan Wood Research Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74146482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ken-ichi Sugimoto, N. Nakamura, Eiichi Fujino, Y. Sano, Satoshi Shindo, Takahisa Kamada, Seiichiro Ukyo, Masaya Gonda
To clarify the static and dynamic properties of large-span wooden floors, we measured static deflection, bending stiffness, natural frequency and damping ratio of floors at four wooden schools and two wooden offices. The initial design deflection to span ratio was approximately 1/430 to 1/1100 for these floors. In addition, design deflections including creep to span ratio was approximately 1/280 to 1/800. These values were within the limitations defined by the Building Standards Law and the Standard for Structural Design of Timber Structures of the Architectural Institute of Japan, except for one elementary school. The experimental bending stiffness of beams or trusses was 1.1 to 3.9 times larger than the design value. On the other hand, the measured natural frequency of floors in actual wooden buildings ranged from 9.5 to 12 Hz. These values could be relatively accurately estimated using the theory of simply supported beams with applied dead loads. Additionally, the damping ratios ranged from 3.1 to 6.5%, almost the same as those in previous studies.
{"title":"Relationship between Vertical Load Properties of Floors and Human Sensory Evaluation of Walking Vibration in Wooden Schools and Offices I.: Static and dynamic properties of large-span wooden floors@@@木造大スパン床の静的および振動性状","authors":"Ken-ichi Sugimoto, N. Nakamura, Eiichi Fujino, Y. Sano, Satoshi Shindo, Takahisa Kamada, Seiichiro Ukyo, Masaya Gonda","doi":"10.2488/JWRS.62.101","DOIUrl":"https://doi.org/10.2488/JWRS.62.101","url":null,"abstract":"To clarify the static and dynamic properties of large-span wooden floors, we measured static deflection, bending stiffness, natural frequency and damping ratio of floors at four wooden schools and two wooden offices. The initial design deflection to span ratio was approximately 1/430 to 1/1100 for these floors. In addition, design deflections including creep to span ratio was approximately 1/280 to 1/800. These values were within the limitations defined by the Building Standards Law and the Standard for Structural Design of Timber Structures of the Architectural Institute of Japan, except for one elementary school. The experimental bending stiffness of beams or trusses was 1.1 to 3.9 times larger than the design value. On the other hand, the measured natural frequency of floors in actual wooden buildings ranged from 9.5 to 12 Hz. These values could be relatively accurately estimated using the theory of simply supported beams with applied dead loads. Additionally, the damping ratios ranged from 3.1 to 6.5%, almost the same as those in previous studies.","PeriodicalId":17248,"journal":{"name":"Journal of the Japan Wood Research Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75288520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kai Moriguchi, Naoaki Shibata, M. Imai, Masato Yamanouchi, Takahisa Yoshida
We defined a knot assessment model based on the visual grading of Japanese Agricultural Standard （JAS） of lumber and attempted to optimize parameters of the model using simulated annealing. Parameters of the knot assessment model were optimized by maximizing coefficients of determination of regression models, using data of bending tests and surface images of 40 test pieces, 120 mm square cross section kiln-dried lumber with pith of Japanese larch （(cid:9488)(cid:9509)(cid:9526)(cid:9517)(cid:9532)(cid:9444)(cid:9519)(cid:9509)(cid:9513)(cid:9521)(cid:9524)(cid:9514)(cid:9513)(cid:9526)(cid:9517) Lamb.）. Values of the coefficient of determination of regression models using knot index values of optimized knot assessment models were much larger than those obtained by ordinary visual grading. However, knot index values of almost all test pieces were decided by a particular type of knot diameter ratio, suggesting overfitting. We then simplified the knot assessment model, eliminating the distinction between center or edge areas and types of single knot. Values of the coefficient of determination of regression models were then decreased compared to those of the above optimized knot assessment models. However, they were still larger than those based on ordinary visual grading, and there were significant differences between correlation coefficients of each single regression model.
{"title":"Optimizing the Parameters of a Knot Assessment Model Based on the Visual Grading of JAS of Lumber","authors":"Kai Moriguchi, Naoaki Shibata, M. Imai, Masato Yamanouchi, Takahisa Yoshida","doi":"10.2488/JWRS.62.133","DOIUrl":"https://doi.org/10.2488/JWRS.62.133","url":null,"abstract":"We defined a knot assessment model based on the visual grading of Japanese Agricultural Standard （JAS） of lumber and attempted to optimize parameters of the model using simulated annealing. Parameters of the knot assessment model were optimized by maximizing coefficients of determination of regression models, using data of bending tests and surface images of 40 test pieces, 120 mm square cross section kiln-dried lumber with pith of Japanese larch （(cid:9488)(cid:9509)(cid:9526)(cid:9517)(cid:9532)(cid:9444)(cid:9519)(cid:9509)(cid:9513)(cid:9521)(cid:9524)(cid:9514)(cid:9513)(cid:9526)(cid:9517) Lamb.）. Values of the coefficient of determination of regression models using knot index values of optimized knot assessment models were much larger than those obtained by ordinary visual grading. However, knot index values of almost all test pieces were decided by a particular type of knot diameter ratio, suggesting overfitting. We then simplified the knot assessment model, eliminating the distinction between center or edge areas and types of single knot. Values of the coefficient of determination of regression models were then decreased compared to those of the above optimized knot assessment models. However, they were still larger than those based on ordinary visual grading, and there were significant differences between correlation coefficients of each single regression model.","PeriodicalId":17248,"journal":{"name":"Journal of the Japan Wood Research Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83543494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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