Masaaki Yuki, T. Momoi, Jun Kobayashi, H. Ohbayashi
The vibrational properties of wood are determined by the free-free flexural vibration or cantilever vibration methods. On the other hand, for damping materials, these properties are generally determined by the central exciting method. The central exciting method is rarely used for wood. In the present study, we measured the dynamic Young’s modulus (E′) and the loss tangent (tanδ) for the same Sitka spruce specimens by the central exciting (JIS-certificated apparatus), the free-free flexural vibration and the cantilever vibration methods, and compared the results from the perspective of the fixed condition, vibrational modes and other aspects. A simplified experimental apparatus for measurement using the central exciting method was also designed and constructed. The simplified experimental apparatus and JIS-certificated apparatus were verified by measured values (E′ and tanδ). Measured values obtained by the simplified apparatus closely matched those obtained by the JIScertificated apparatus. The E′ values obtained by the central exciting method closely matched those obtained by the free-free flexural vibration method. The tanδ values obtained by the central exciting method were higher than those obtained by the free-free flexural vibration method but close to those obtained by the cantilever vibration method.
{"title":"Measurement of Wood Vibrational Properties by the Central Exciting Method","authors":"Masaaki Yuki, T. Momoi, Jun Kobayashi, H. Ohbayashi","doi":"10.2488/JWRS.63.196","DOIUrl":"https://doi.org/10.2488/JWRS.63.196","url":null,"abstract":"The vibrational properties of wood are determined by the free-free flexural vibration or cantilever vibration methods. On the other hand, for damping materials, these properties are generally determined by the central exciting method. The central exciting method is rarely used for wood. In the present study, we measured the dynamic Young’s modulus (E′) and the loss tangent (tanδ) for the same Sitka spruce specimens by the central exciting (JIS-certificated apparatus), the free-free flexural vibration and the cantilever vibration methods, and compared the results from the perspective of the fixed condition, vibrational modes and other aspects. A simplified experimental apparatus for measurement using the central exciting method was also designed and constructed. The simplified experimental apparatus and JIS-certificated apparatus were verified by measured values (E′ and tanδ). Measured values obtained by the simplified apparatus closely matched those obtained by the JIScertificated apparatus. The E′ values obtained by the central exciting method closely matched those obtained by the free-free flexural vibration method. The tanδ values obtained by the central exciting method were higher than those obtained by the free-free flexural vibration method but close to those obtained by the cantilever vibration method.","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":"86180412","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}
Harusa Tsutsumi, Shunji Oribe, H. Haga, T. Fujimoto
The objective of this study was to estimate the moisture content, wood density of corresponding moisture content and modulus of elasticity in standing trees using vibrational spectra. For the preliminary tests, fixed length and diameter logs were used for the following experiments. The logs were impregnated with water at normal pressure and the vibration tests were carried out at fixed intervals while the logs were left to dry under room conditions. The statistical models for the prediction of the wood properties were built using the vibration spectra generated from three excitation methods, namely, excitation of longitudinal vibration by hitting the transverse surface of logs, and excitation of lateral vibration or longitudinal vibration by hitting the log’s lateral surface. The Lasso (least absolute shrinkage and selection operator) and PLS (partial least squares) models could predict the moisture content and density independently of the excitation, with the exception of the modulus of elasticity. The vibrational spectra obtained by hitting the lateral surface of logs could give good prediction models, indicating that the techniques suggested in this study have high potential for application to standing trees.
{"title":"Nondestructive Evaluation of Wood Properties in Standing Trees Using Vibrational Spectra","authors":"Harusa Tsutsumi, Shunji Oribe, H. Haga, T. Fujimoto","doi":"10.2488/JWRS.63.291","DOIUrl":"https://doi.org/10.2488/JWRS.63.291","url":null,"abstract":"The objective of this study was to estimate the moisture content, wood density of corresponding moisture content and modulus of elasticity in standing trees using vibrational spectra. For the preliminary tests, fixed length and diameter logs were used for the following experiments. The logs were impregnated with water at normal pressure and the vibration tests were carried out at fixed intervals while the logs were left to dry under room conditions. The statistical models for the prediction of the wood properties were built using the vibration spectra generated from three excitation methods, namely, excitation of longitudinal vibration by hitting the transverse surface of logs, and excitation of lateral vibration or longitudinal vibration by hitting the log’s lateral surface. The Lasso (least absolute shrinkage and selection operator) and PLS (partial least squares) models could predict the moisture content and density independently of the excitation, with the exception of the modulus of elasticity. The vibrational spectra obtained by hitting the lateral surface of logs could give good prediction models, indicating that the techniques suggested in this study have high potential for application to standing trees.","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":"88151834","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}
The objective of this study was to develop a nondestructive method using X-rays for evaluating the distribution of adhesive resin in laminated timber glued with a water-based polymer-isocyanate adhesive (glulam). X-ray radiographs of laboratory-produced glulam were taken before and after gluing. The distribution of adhesive resin in glulam was evaluated by comparing brightness values on the radiographs. Two validation experiments revealed that the method showed high accuracy in estimating both the average and local spread rate and could provide a clear visualization of quantitative trends in the distribution of resin in glulam. The method allows us to nondestructively evaluate the distribution of the studied adhesive resin in each glulam, suggesting that X-rays are not only useful for various fundamental studies relating to wood adhesives but also suitable for industrial application..
{"title":"Nondestructive Evaluation of Water-based Polymer-isocyanate Adhesive Distribution in Glued Laminated Timber Using X-rays","authors":"Ayaka Murai, Takashi Tanaka, M. Yamada","doi":"10.2488/JWRS.63.119","DOIUrl":"https://doi.org/10.2488/JWRS.63.119","url":null,"abstract":"The objective of this study was to develop a nondestructive method using X-rays for evaluating the distribution of adhesive resin in laminated timber glued with a water-based polymer-isocyanate adhesive (glulam). X-ray radiographs of laboratory-produced glulam were taken before and after gluing. The distribution of adhesive resin in glulam was evaluated by comparing brightness values on the radiographs. Two validation experiments revealed that the method showed high accuracy in estimating both the average and local spread rate and could provide a clear visualization of quantitative trends in the distribution of resin in glulam. The method allows us to nondestructively evaluate the distribution of the studied adhesive resin in each glulam, suggesting that X-rays are not only useful for various fundamental studies relating to wood adhesives but also suitable for industrial application..","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":"74351567","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}
Rie Yamashita, S. Sakuragawa, Yukie Saito, Hiromu Watanabe, M. Yasumura
The change over time of the indoor air quality of a special elderly nursing home made of wood was investigated. The direct measurement of indoor air revealed that the main component was terpenes, a known source of woody aromas. The contribution of each part of the woody interior to the quality of the indoor air was investigated using an emission test cell method. The results showed that α -Pinene, the main component of the detected terpenes, was emitted from Hinoki timber used for the post and brace, and that sesquiterpenes （ α -Muurolene, Calamenene, δ-Cadinene, etc.）, which counted for 10-40% of the detected aroma, were emitted from the sugi lumber used for flooring and roof sheathing. A year after construction, the concentrations of some sesquiterpenes, including Calamenene, which is a source of woody aromas, had increased although the total amount of terpenes had decreased. Consequently, it was found that of the indoor air components the woody aroma mainly derives from terpenes.
{"title":"Formation of Quality Indoor Air in Wooden Buildings with Domestic Wood","authors":"Rie Yamashita, S. Sakuragawa, Yukie Saito, Hiromu Watanabe, M. Yasumura","doi":"10.2488/JWRS.63.86","DOIUrl":"https://doi.org/10.2488/JWRS.63.86","url":null,"abstract":"The change over time of the indoor air quality of a special elderly nursing home made of wood was investigated. The direct measurement of indoor air revealed that the main component was terpenes, a known source of woody aromas. The contribution of each part of the woody interior to the quality of the indoor air was investigated using an emission test cell method. The results showed that α -Pinene, the main component of the detected terpenes, was emitted from Hinoki timber used for the post and brace, and that sesquiterpenes （ α -Muurolene, Calamenene, δ-Cadinene, etc.）, which counted for 10-40% of the detected aroma, were emitted from the sugi lumber used for flooring and roof sheathing. A year after construction, the concentrations of some sesquiterpenes, including Calamenene, which is a source of woody aromas, had increased although the total amount of terpenes had decreased. Consequently, it was found that of the indoor air components the woody aroma mainly derives from terpenes.","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":"85123822","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}
Wooden living environments are widely held to be human-friendly, warm, and relaxing. However, the scientific evidence supporting this social image is still sparse. Recently, there has been a growing desire among industry representatives, policy-makers, and consumers for scientific research that eluci-dates the positive influences of wood and wooden interiors in structures intended for human occupa-tion. The aim of this review is to provide an overview of relatively recent research that examines human responses to wood in various living environments, with a focus on the methods used in such studies. We also review the methodologies used in several studies that have been conducted in related fields, such as architecture and public health, in terms of their applicability to the evaluation of wooden environments. Based on our review of the current state of research, we further consider future chal-lenges that lie ahead in this field. These include accumulating data on vulnerable groups and individu-als for a short-term exposure to wooden environments and exploring approaches to elucidate interme-diate and longer-term impacts of wooden environments on health and well-being.
{"title":"Evaluation of the Impact of Wooden Living Environments on Humans","authors":"Y. Tsunetsugu, Eri Matsubara, M. Sugiyama","doi":"10.2488/JWRS.63.1","DOIUrl":"https://doi.org/10.2488/JWRS.63.1","url":null,"abstract":"Wooden living environments are widely held to be human-friendly, warm, and relaxing. However, the scientific evidence supporting this social image is still sparse. Recently, there has been a growing desire among industry representatives, policy-makers, and consumers for scientific research that eluci-dates the positive influences of wood and wooden interiors in structures intended for human occupa-tion. The aim of this review is to provide an overview of relatively recent research that examines human responses to wood in various living environments, with a focus on the methods used in such studies. We also review the methodologies used in several studies that have been conducted in related fields, such as architecture and public health, in terms of their applicability to the evaluation of wooden environments. Based on our review of the current state of research, we further consider future chal-lenges that lie ahead in this field. These include accumulating data on vulnerable groups and individu-als for a short-term exposure to wooden environments and exploring approaches to elucidate interme-diate and longer-term impacts of wooden environments on health and well-being.","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":"79614385","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}
R. Noda, Chihiro Kayo, Masato Yamanouchi, Naoaki Shibata
{"title":"Life Cycle Greenhouse Gas Emissions of Wooden Roadside Noise Barriers in Nagano Prefecture","authors":"R. Noda, Chihiro Kayo, Masato Yamanouchi, Naoaki Shibata","doi":"10.2488/JWRS.63.41","DOIUrl":"https://doi.org/10.2488/JWRS.63.41","url":null,"abstract":"","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":"84950802","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}
K. Shimizu, Yuri Yoshimura, T. Nakagawa, Sayaka Matsumoto, Yuki Washioka, Eriko Haga, Akiyoshi Honden, T. Nakashima, H. Saijo, K. Fujita, Yuichiro Watanabe, G. Okamoto, Shinshi Inoue, Shinji Yasunari, J. Nagano, Yuki Yamada, T. Okamoto, Koichiro Onuki, H. Ishikawa, N. Fujimoto
{"title":"Analysis of Volatile Compounds and Their Seasonal Changes in Rooms Using Sugi ( Cryptomeria japonica ) Wood Boards as Interior Materials","authors":"K. Shimizu, Yuri Yoshimura, T. Nakagawa, Sayaka Matsumoto, Yuki Washioka, Eriko Haga, Akiyoshi Honden, T. Nakashima, H. Saijo, K. Fujita, Yuichiro Watanabe, G. Okamoto, Shinshi Inoue, Shinji Yasunari, J. Nagano, Yuki Yamada, T. Okamoto, Koichiro Onuki, H. Ishikawa, N. Fujimoto","doi":"10.2488/JWRS.63.126","DOIUrl":"https://doi.org/10.2488/JWRS.63.126","url":null,"abstract":"","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":"86989248","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":"Outdoor Exposure Test for Sugi Glued-Laminated Timber Manufactured Using 7 Adhesive Resins I.: Shear strength and wood failure ratio@@@せん断強度および木部破断率","authors":"Y. Yanagawa, Mitsuyoshi Harata","doi":"10.2488/JWRS.63.34","DOIUrl":"https://doi.org/10.2488/JWRS.63.34","url":null,"abstract":"","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":"81195115","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. Ido, Hideo Kato, H. Nagao, Masaki Harada, Y. Ikami, Yukari Matsumura, Y. Matsuda, S. Saito
In this study, we assessed the grades and mechanical properties of dimension lumber with size classifications of 206, measuring 38-mm thickness and 140-mm width, and 306, measuring 64-mm thickness and 140-mm width, for wood-frame construction, as obtained from 31 large-diameter sugi (Cryptomeria japonica) logs. The lumber, graded as class A in the Japanese Agricultural Standard (JAS), is visually graded dimension lumber primarily used for members requiring high bending performance. Numerous types of lumber have been ranked as select structural grade in terms of both size classifications. However, the ratio of select structural grade is higher in 306 than in 206. The mechanical properties of the lumber in each size classification showed no significant differences. In this study, by conducting bending tests, we investigated the effect of loading configuration, for which an international standardization is planned, with respect to the mechanical properties. Three loading configurations (JAS, an international standard, and a different standard) were employed, and we found that the value of the Young’s modulus in static bending could be adjusted using the adjustment ratios mentioned in the JAS, irrespective of the type of loading configuration used. Our bending test results for different loading configurations showed small differences in bending strength. The 5th percentile lower limits of bending strength in both the 206 and 306 size classifications fell slightly below the specified design strength by the Ministry of Land, Infrastructure, Transport and Tourism. Finally, to facilitate the efficient collection of lumber from large-diameter logs, we compared the amount of lumber of class A, No. 2 grade and better obtained from logs via the estimation and measurement methods and found that the results matched well. As such, we can conclude that the estimation method is beneficial.
{"title":"Grades and Mechanical Properties of Dimension Lumber for Wood Frame Construction Obtained from Large-diameter Sugi ( Cryptomeria japonica ) Logs","authors":"H. Ido, Hideo Kato, H. Nagao, Masaki Harada, Y. Ikami, Yukari Matsumura, Y. Matsuda, S. Saito","doi":"10.2488/JWRS.63.282","DOIUrl":"https://doi.org/10.2488/JWRS.63.282","url":null,"abstract":"In this study, we assessed the grades and mechanical properties of dimension lumber with size classifications of 206, measuring 38-mm thickness and 140-mm width, and 306, measuring 64-mm thickness and 140-mm width, for wood-frame construction, as obtained from 31 large-diameter sugi (Cryptomeria japonica) logs. The lumber, graded as class A in the Japanese Agricultural Standard (JAS), is visually graded dimension lumber primarily used for members requiring high bending performance. Numerous types of lumber have been ranked as select structural grade in terms of both size classifications. However, the ratio of select structural grade is higher in 306 than in 206. The mechanical properties of the lumber in each size classification showed no significant differences. In this study, by conducting bending tests, we investigated the effect of loading configuration, for which an international standardization is planned, with respect to the mechanical properties. Three loading configurations (JAS, an international standard, and a different standard) were employed, and we found that the value of the Young’s modulus in static bending could be adjusted using the adjustment ratios mentioned in the JAS, irrespective of the type of loading configuration used. Our bending test results for different loading configurations showed small differences in bending strength. The 5th percentile lower limits of bending strength in both the 206 and 306 size classifications fell slightly below the specified design strength by the Ministry of Land, Infrastructure, Transport and Tourism. Finally, to facilitate the efficient collection of lumber from large-diameter logs, we compared the amount of lumber of class A, No. 2 grade and better obtained from logs via the estimation and measurement methods and found that the results matched well. As such, we can conclude that the estimation method is beneficial.","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":"84838704","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}
Kaori Mimura, T. Hara, Hideo Kato, M. Noguchi, A. Hirata, K. Honda, T. Matsuhashi
When demolishing a structure, reusable and secondary materials are obtained, such as lumps of as-phalt and concrete, including articles of excavated construction wood. Most especially, waste woods should be aimed at recycling with the view of effective utilization of resources, controlling wastes generated and conserving the environment. However, they are disposed of as industrial wastes in many cases, because specific uses and methods are not standardized. On the other hand, underground use of wood for the purpose of ground improvement has been suggested as new utilization of logs in large quantities. However, there are few cases in which logs excavated from construction sites are recycled for underground use because their strength and soundness cannot be specified. This study suggests an economical judging method by which timbers generated during construction that would be available for recycling can be identified on site by including excavated materials generated from locations with high moisture content because always being buried in water. wood, youngʼs modulus, longitudinal vibration test
{"title":"Reuse of Wood Used in Underground Construction and Suggestion of a Method of Differentiation","authors":"Kaori Mimura, T. Hara, Hideo Kato, M. Noguchi, A. Hirata, K. Honda, T. Matsuhashi","doi":"10.2488/JWRS.63.214","DOIUrl":"https://doi.org/10.2488/JWRS.63.214","url":null,"abstract":"When demolishing a structure, reusable and secondary materials are obtained, such as lumps of as-phalt and concrete, including articles of excavated construction wood. Most especially, waste woods should be aimed at recycling with the view of effective utilization of resources, controlling wastes generated and conserving the environment. However, they are disposed of as industrial wastes in many cases, because specific uses and methods are not standardized. On the other hand, underground use of wood for the purpose of ground improvement has been suggested as new utilization of logs in large quantities. However, there are few cases in which logs excavated from construction sites are recycled for underground use because their strength and soundness cannot be specified. This study suggests an economical judging method by which timbers generated during construction that would be available for recycling can be identified on site by including excavated materials generated from locations with high moisture content because always being buried in water. wood, youngʼs modulus, longitudinal vibration test","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":"85295679","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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