In a situation where the development of various novel wooden structural materials continues, it becomes necessary to understand the creep properties of wooden screw joints under shear loading. Therefore, shear creep tests for joint specimens were conducted. Screw joint specimens consisting of solid wood (Japanese cypress) and structural plywood made of softwood were used for the tests. The tests were conducted in a testing room controlled at 20 °C temperature and 65% relative humidity. The shear load was applied for over 40000 hours. The stress levels were determined as 39.0-70.2% of the standard yield load obtained by monotonic-loading tests. The slip-time relationships were obtained by the tests. This study proposed a method for estimating the creep limit by analyzing the slip-time relationships. By applying the proposed method, the creep limit of the screw joint specimens was estimated as 27.6% of the yield load.
{"title":"Estimation of Creep Limit of Screw Joints between Timber and Structural Plywood under Constant Shear Loading","authors":"Keita Ogawa, K. Kobayashi","doi":"10.2488/jwrs.66.187","DOIUrl":"https://doi.org/10.2488/jwrs.66.187","url":null,"abstract":"In a situation where the development of various novel wooden structural materials continues, it becomes necessary to understand the creep properties of wooden screw joints under shear loading. Therefore, shear creep tests for joint specimens were conducted. Screw joint specimens consisting of solid wood (Japanese cypress) and structural plywood made of softwood were used for the tests. The tests were conducted in a testing room controlled at 20 °C temperature and 65% relative humidity. The shear load was applied for over 40000 hours. The stress levels were determined as 39.0-70.2% of the standard yield load obtained by monotonic-loading tests. The slip-time relationships were obtained by the tests. This study proposed a method for estimating the creep limit by analyzing the slip-time relationships. By applying the proposed method, the creep limit of the screw joint specimens was estimated as 27.6% of the yield load.","PeriodicalId":49800,"journal":{"name":"Mokuzai Gakkaishi","volume":" ","pages":""},"PeriodicalIF":0.3,"publicationDate":"2020-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46775686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Ohshima, Hiroyuki Sugimoto, M. Sugimori, Emika Sawada
In order to clarify the mechanism of change in reflectance of visible light due to painting treatment, X-ray CT observations of the internal structure of the material and measurements of the optical properties of visible light with a spectrophotometer were performed for two types of grain of hinoki cypress (Chamaecyparis obtusa) with various amounts of paint. In the observation of CT images, penetration of the paint into the material was not confirmed in the edge-grain samples, whereas that was confirmed in the end-grain samples. In addition, the permeability of the paint of the end-grain samples was quantified, and that was in a positive relationship with the paint amount. In the optical characteristics measurements, in the medium to long wavelength range, there was no increase in absorption but a decrease in reflectance due to an increase of transmittance. There was also a decrease in reflectance due to an increase in the amount of penetration. From the above results, it was shown that the mechanism of lightness reduction by the clear painting treatment is affected by an increase in the value of the transmittance in the medium to long wavelength regions due to differences in the amount of paint penetration.
{"title":"Effect of Painting Treatment on Visible Light Reflection Considering Cellular Structure Inside Wood","authors":"K. Ohshima, Hiroyuki Sugimoto, M. Sugimori, Emika Sawada","doi":"10.2488/jwrs.66.202","DOIUrl":"https://doi.org/10.2488/jwrs.66.202","url":null,"abstract":"In order to clarify the mechanism of change in reflectance of visible light due to painting treatment, X-ray CT observations of the internal structure of the material and measurements of the optical properties of visible light with a spectrophotometer were performed for two types of grain of hinoki cypress (Chamaecyparis obtusa) with various amounts of paint. In the observation of CT images, penetration of the paint into the material was not confirmed in the edge-grain samples, whereas that was confirmed in the end-grain samples. In addition, the permeability of the paint of the end-grain samples was quantified, and that was in a positive relationship with the paint amount. In the optical characteristics measurements, in the medium to long wavelength range, there was no increase in absorption but a decrease in reflectance due to an increase of transmittance. There was also a decrease in reflectance due to an increase in the amount of penetration. From the above results, it was shown that the mechanism of lightness reduction by the clear painting treatment is affected by an increase in the value of the transmittance in the medium to long wavelength regions due to differences in the amount of paint penetration.","PeriodicalId":49800,"journal":{"name":"Mokuzai Gakkaishi","volume":" ","pages":""},"PeriodicalIF":0.3,"publicationDate":"2020-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47938080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this research, asymmetric four-point bending (AFPB) tests were conducted to obtain the shear strength of Japanese cedar using straight specimens. During the AFPB tests, the locations of the supporting and loading points were varied along the length direction of the specimen at fixed configurations. In contrast, the AFPB test was also conducted using notched specimens, and the obtained shear strengths were compared with those obtained using straight specimens. The shear strength values obtained from straight specimen were similar to those using notched specimens when the supporting and loading points were in a certain range.
{"title":"Effect of Supporting and Loading Locations on the Shear Strength of Solid Wood Obtained by Asymmetric Four-point Bending Tests","authors":"H. Yoshihara, Masahiro Yoshinobu","doi":"10.2488/jwrs.66.209","DOIUrl":"https://doi.org/10.2488/jwrs.66.209","url":null,"abstract":"In this research, asymmetric four-point bending (AFPB) tests were conducted to obtain the shear strength of Japanese cedar using straight specimens. During the AFPB tests, the locations of the supporting and loading points were varied along the length direction of the specimen at fixed configurations. In contrast, the AFPB test was also conducted using notched specimens, and the obtained shear strengths were compared with those obtained using straight specimens. The shear strength values obtained from straight specimen were similar to those using notched specimens when the supporting and loading points were in a certain range.","PeriodicalId":49800,"journal":{"name":"Mokuzai Gakkaishi","volume":" ","pages":""},"PeriodicalIF":0.3,"publicationDate":"2020-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42692204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Y. Kita, Suyako Tazuru, Hironobu Takeshita, J. Sugiyama
Near-infrared spectroscopy enables identification of previously inseparable wood species by the observation of their anatomical features by optical microscopy and through the detection of subtle differences of chemical components between wood species. This research verified whether the combination of Near-Infrared spectroscopy, multivariate analysis and feature selection method can discriminate the anatomically similar and important softwood species used as building materials, (cid:9479)(cid:9516)(cid:9509)(cid:9521)(cid:9509)(cid:9513)(cid:9511)(cid:9533)(cid:9524)(cid:9509)(cid:9526)(cid:9517)(cid:9527)(cid:9444)(cid:9523)(cid:9510)(cid:9528)(cid:9529)(cid:9527)(cid:9509) and (cid:9496)(cid:9516)(cid:9529)(cid:9518)(cid:9523)(cid:9524)(cid:9527)(cid:9517)(cid:9527) spp., and (cid:9496)(cid:9527)(cid:9529)(cid:9515)(cid:9509)(cid:9444)(cid:9527)(cid:9517)(cid:9513)(cid:9510)(cid:9523)(cid:9520)(cid:9512)(cid:9517)(cid:9517)
{"title":"Classification of Wood Species Frequently Used for Modern and Ancient Buildings Utilizing Near-Infrared Spectroscopy with Multivariate Analysis and Enhancement of Its Generalization Performance","authors":"Y. Kita, Suyako Tazuru, Hironobu Takeshita, J. Sugiyama","doi":"10.2488/jwrs.66.171","DOIUrl":"https://doi.org/10.2488/jwrs.66.171","url":null,"abstract":"Near-infrared spectroscopy enables identification of previously inseparable wood species by the observation of their anatomical features by optical microscopy and through the detection of subtle differences of chemical components between wood species. This research verified whether the combination of Near-Infrared spectroscopy, multivariate analysis and feature selection method can discriminate the anatomically similar and important softwood species used as building materials, (cid:9479)(cid:9516)(cid:9509)(cid:9521)(cid:9509)(cid:9513)(cid:9511)(cid:9533)(cid:9524)(cid:9509)(cid:9526)(cid:9517)(cid:9527)(cid:9444)(cid:9523)(cid:9510)(cid:9528)(cid:9529)(cid:9527)(cid:9509) and (cid:9496)(cid:9516)(cid:9529)(cid:9518)(cid:9523)(cid:9524)(cid:9527)(cid:9517)(cid:9527) spp., and (cid:9496)(cid:9527)(cid:9529)(cid:9515)(cid:9509)(cid:9444)(cid:9527)(cid:9517)(cid:9513)(cid:9510)(cid:9523)(cid:9520)(cid:9512)(cid:9517)(cid:9517)","PeriodicalId":49800,"journal":{"name":"Mokuzai Gakkaishi","volume":" ","pages":""},"PeriodicalIF":0.3,"publicationDate":"2020-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44201472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ryutaro Sudo, H. Kawahara, Y. Ochiai, K. Aoki, Masahiro Inayama
There are two formulas for the allowable resistance of nailed joints. One is based on the European Yield Theory (EYT) and the other contains the head diameter of the nail as a parameter. In addition, there are a few cases where the behavior of the load rising after yield is considered theoretically. In this paper, we estimated yield and maximum load of nailed joints with MDF. The yield load was estimated by the EYT formula considering the moment generated by nail head rotation. The maximum load was estimated by the existing formula of screw joints considering a “rope effect”. As a result, the estimation accuracy was increased by the improved EYT formula, taking into consideration the moment generated by nail head rotation. It was also shown that the rope effect of nailed joints can be estimated by the formula for screw joints. On the other hand, it was suggested that the bearing strength of the range between the plastic hinge and the tip of the nail might affect the gap of yield strength between the calculated and the experimental values. It was also suggested that, at the maximum load, nail withdrawal strength might be underestimated and nail-head pullthrough strength be overestimated compared to actual values.
{"title":"Study of Single Shear Performance of Nailed Joints for Structural Utilization of MDF II.","authors":"Ryutaro Sudo, H. Kawahara, Y. Ochiai, K. Aoki, Masahiro Inayama","doi":"10.2488/jwrs.66.128","DOIUrl":"https://doi.org/10.2488/jwrs.66.128","url":null,"abstract":"There are two formulas for the allowable resistance of nailed joints. One is based on the European Yield Theory (EYT) and the other contains the head diameter of the nail as a parameter. In addition, there are a few cases where the behavior of the load rising after yield is considered theoretically. In this paper, we estimated yield and maximum load of nailed joints with MDF. The yield load was estimated by the EYT formula considering the moment generated by nail head rotation. The maximum load was estimated by the existing formula of screw joints considering a “rope effect”. As a result, the estimation accuracy was increased by the improved EYT formula, taking into consideration the moment generated by nail head rotation. It was also shown that the rope effect of nailed joints can be estimated by the formula for screw joints. On the other hand, it was suggested that the bearing strength of the range between the plastic hinge and the tip of the nail might affect the gap of yield strength between the calculated and the experimental values. It was also suggested that, at the maximum load, nail withdrawal strength might be underestimated and nail-head pullthrough strength be overestimated compared to actual values.","PeriodicalId":49800,"journal":{"name":"Mokuzai Gakkaishi","volume":"1 1","pages":""},"PeriodicalIF":0.3,"publicationDate":"2020-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41557087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tomoya Murano, N. Fujimoto, T. Nakao, Hiroki Sakagami, Kenei Watanabe
In this study, the surface-strain distribution behavior of sugi (Cryptomeria japonica) square timber under high-temperature drying was determined. The surface-strain distribution was measured using the mark-tracking method, which is an image analysis technique. Boxed-heart and pithless timbers with a cross-sectional dimension of 132 mm × 132 mm were dried under three types of drying condition. In each condition, the values of surface strain at the center of the timber were higher than those at the edge. This tendency was remarkable in the case of high-temperature drying of boxedheart timber. The surface drying set, which was measured after drying, showed a positive correlation to the surface strain. This indicated that the surface strain could be used to rough estimation of the amount of the drying set under kiln drying. By measuring the surface-strain distribution using the image analysis technique, the temporal change in the surface strain during the high-temperature drying was clarified in detail.
{"title":"Temporal Change in Surface-strain Distribution of Sugi (Cryptomeria japonica) Square Timber during High-Temperature Drying","authors":"Tomoya Murano, N. Fujimoto, T. Nakao, Hiroki Sakagami, Kenei Watanabe","doi":"10.2488/jwrs.66.140","DOIUrl":"https://doi.org/10.2488/jwrs.66.140","url":null,"abstract":"In this study, the surface-strain distribution behavior of sugi (Cryptomeria japonica) square timber under high-temperature drying was determined. The surface-strain distribution was measured using the mark-tracking method, which is an image analysis technique. Boxed-heart and pithless timbers with a cross-sectional dimension of 132 mm × 132 mm were dried under three types of drying condition. In each condition, the values of surface strain at the center of the timber were higher than those at the edge. This tendency was remarkable in the case of high-temperature drying of boxedheart timber. The surface drying set, which was measured after drying, showed a positive correlation to the surface strain. This indicated that the surface strain could be used to rough estimation of the amount of the drying set under kiln drying. By measuring the surface-strain distribution using the image analysis technique, the temporal change in the surface strain during the high-temperature drying was clarified in detail.","PeriodicalId":49800,"journal":{"name":"Mokuzai Gakkaishi","volume":" ","pages":""},"PeriodicalIF":0.3,"publicationDate":"2020-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49627767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Y. Hirano, T. Saitoh, E. Fukatsu, Hajime Kobayashi, H. Muraoka, Yudong Shen, K. Yasue
We investigated the effects of climate factors on tree-ring structure 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) in central Japan. We collected cores from 33 plantation trees in the Takayama evergreen coniferous forest site at Gifu University and measured annual ring width （RW）, annual mean density （RD）, earlywood width （EW）, latewood width （LW）, earlywood density （ED） and latewood density （LD） by X-ray densitometry. We also calculated annual ring weight growth （RWG） by multiplying RW and RD. We developed seven residual chronologies of the parameters of tree-ring structure by a dendroecological method. Pearsonʼs correlation analysis was applied to assess relationships among the chronologies, and relationships between the chronologies and climatic factors. EW showed significant positive correlations with RW and RWG. Moreover, EW showed significant positive correlation with the temperature current from March to April. These results indicate that EW is the most dominant factor which regulates RW and RWG of (cid:9479)(cid:9458)(cid:9444)(cid:9518)(cid:9509)(cid:9524)(cid:9523)(cid:9522)(cid:9517)(cid:9511)(cid:9509)(cid:9458) It is suggested that EW increases by the temperature rise of early spring before reactivation of cambium activity, and subsequently RW and RWG will increase.
{"title":"Effects of Climate Factors on the Tree-ring Structure of Cryptomeria japonica in Central Japan","authors":"Y. Hirano, T. Saitoh, E. Fukatsu, Hajime Kobayashi, H. Muraoka, Yudong Shen, K. Yasue","doi":"10.2488/jwrs.66.117","DOIUrl":"https://doi.org/10.2488/jwrs.66.117","url":null,"abstract":"We investigated the effects of climate factors on tree-ring structure 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) in central Japan. We collected cores from 33 plantation trees in the Takayama evergreen coniferous forest site at Gifu University and measured annual ring width （RW）, annual mean density （RD）, earlywood width （EW）, latewood width （LW）, earlywood density （ED） and latewood density （LD） by X-ray densitometry. We also calculated annual ring weight growth （RWG） by multiplying RW and RD. We developed seven residual chronologies of the parameters of tree-ring structure by a dendroecological method. Pearsonʼs correlation analysis was applied to assess relationships among the chronologies, and relationships between the chronologies and climatic factors. EW showed significant positive correlations with RW and RWG. Moreover, EW showed significant positive correlation with the temperature current from March to April. These results indicate that EW is the most dominant factor which regulates RW and RWG of (cid:9479)(cid:9458)(cid:9444)(cid:9518)(cid:9509)(cid:9524)(cid:9523)(cid:9522)(cid:9517)(cid:9511)(cid:9509)(cid:9458) It is suggested that EW increases by the temperature rise of early spring before reactivation of cambium activity, and subsequently RW and RWG will increase.","PeriodicalId":49800,"journal":{"name":"Mokuzai Gakkaishi","volume":" ","pages":""},"PeriodicalIF":0.3,"publicationDate":"2020-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44044374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Evaluation of Greenhouse Gas Emissions Associated with Lumber Products from Sawmills in Mie Prefecture, Japan","authors":"Yuki Fuchigami, Takahisa Nakai","doi":"10.2488/jwrs.66.161","DOIUrl":"https://doi.org/10.2488/jwrs.66.161","url":null,"abstract":"","PeriodicalId":49800,"journal":{"name":"Mokuzai Gakkaishi","volume":" ","pages":""},"PeriodicalIF":0.3,"publicationDate":"2020-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47669734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the present study, new high-performance strapped adhesive plates comprising of hinoki cypress (Chamaecyparis obtusa) and bamboo (Phyllostachys heterocycla) were investigated. Such plates are expected to find applications in making furniture or house wall construction. Two test set-up were performed, single-strap joint and double-strap joint. In the single-strap joint set-up, one bamboo plate was glued to one side of two abutting hinoki plates. Two thickness bamboo plate variables were tested, using 4 and 2 mm. On the other hand, in the double-strap joint set-up, two identical size bamboo plates were glued to both side of the two abutting plates. Two thickness bamboo plate variables were also tested, 4 and 2 mm. In all set-up, the hinoki plates were not bonded to each other. The joints were subjected to tensile strength tests until peeling, and the results were compared. In addition, the stress and strain were calculated using an elastic and orthotropic finite element method (FEM). It was found that the tensile load at rupture for a double-strap joint was not affected by the thickness of the bamboo plates. On the other hand, for a single-strap joint the thickness of the bamboo plates affects the tensile load at rupture. When the single-strap joint with thin bamboo plate was ruptured, the tensile load was larger than that of the more rigid thick bamboo plate. It was found that the stress around the adhesive layer of the joint with lower rigidity plate is smaller by flexibly deforming the bonded part under tensile loadings.
{"title":"Strength and Stress of the Strapped Adhesive Joints made of Hinoki Cypress and Bamboo Plate under Tensile Loadings","authors":"Y. Tsuchiya, N. Nakayama, I. Higuchi","doi":"10.2488/jwrs.66.148","DOIUrl":"https://doi.org/10.2488/jwrs.66.148","url":null,"abstract":"In the present study, new high-performance strapped adhesive plates comprising of hinoki cypress (Chamaecyparis obtusa) and bamboo (Phyllostachys heterocycla) were investigated. Such plates are expected to find applications in making furniture or house wall construction. Two test set-up were performed, single-strap joint and double-strap joint. In the single-strap joint set-up, one bamboo plate was glued to one side of two abutting hinoki plates. Two thickness bamboo plate variables were tested, using 4 and 2 mm. On the other hand, in the double-strap joint set-up, two identical size bamboo plates were glued to both side of the two abutting plates. Two thickness bamboo plate variables were also tested, 4 and 2 mm. In all set-up, the hinoki plates were not bonded to each other. The joints were subjected to tensile strength tests until peeling, and the results were compared. In addition, the stress and strain were calculated using an elastic and orthotropic finite element method (FEM). It was found that the tensile load at rupture for a double-strap joint was not affected by the thickness of the bamboo plates. On the other hand, for a single-strap joint the thickness of the bamboo plates affects the tensile load at rupture. When the single-strap joint with thin bamboo plate was ruptured, the tensile load was larger than that of the more rigid thick bamboo plate. It was found that the stress around the adhesive layer of the joint with lower rigidity plate is smaller by flexibly deforming the bonded part under tensile loadings.","PeriodicalId":49800,"journal":{"name":"Mokuzai Gakkaishi","volume":" ","pages":""},"PeriodicalIF":0.3,"publicationDate":"2020-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45277549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Naoyuki Furuta, Kamii Nakamura, Y. Hirabayashi, J. Miyazaki, Kazushige Matsumoto
The aim of this study was to examine the effect of the radial location of veneer on the strength properties of laminated veneer lumber (LVL) in Japanese larch grown in Hokkaido. We manufactured LVL using veneers taken from different radial locations in logs, and then examined their strength properties using bending and horizontal shear tests. In addition, we examined how annual ring width of the logs influences the modulus of elasticity of both the logs and the veneers. Our results suggested that there was a significant negative correlation (p < 0.01) between the average annual ring width and the modulus of elasticity of the logs. The modulus of elasticity of veneers (EV) increased as distance from the center of the veneer lathe spindle increased, and average EV was higher for logs with lower average annual ring width. In addition, we compared the strength properties of LVL composed of veneers sourced from the outer part of logs (>12 cm from the center of the veneer lathe spindle) with that sourced from the inner part of logs (<10 cm from the center of the veneer lathe spindle). LVL composed of the outer veneers was stronger than that composed of the inner veneers; 53% higher in modulus of elasticity, 65% higher in bending strength, and 26% higher in nominal shear strength. These results indicate that veneer sorting by radial location in logs is effective.
{"title":"The Effects of Veneer Selection by Radial Location in Logs on Strength Properties of LVL in Japanese Larch (Larix kaempferi) Planted in Hokkaido","authors":"Naoyuki Furuta, Kamii Nakamura, Y. Hirabayashi, J. Miyazaki, Kazushige Matsumoto","doi":"10.2488/jwrs.66.93","DOIUrl":"https://doi.org/10.2488/jwrs.66.93","url":null,"abstract":"The aim of this study was to examine the effect of the radial location of veneer on the strength properties of laminated veneer lumber (LVL) in Japanese larch grown in Hokkaido. We manufactured LVL using veneers taken from different radial locations in logs, and then examined their strength properties using bending and horizontal shear tests. In addition, we examined how annual ring width of the logs influences the modulus of elasticity of both the logs and the veneers. Our results suggested that there was a significant negative correlation (p < 0.01) between the average annual ring width and the modulus of elasticity of the logs. The modulus of elasticity of veneers (EV) increased as distance from the center of the veneer lathe spindle increased, and average EV was higher for logs with lower average annual ring width. In addition, we compared the strength properties of LVL composed of veneers sourced from the outer part of logs (>12 cm from the center of the veneer lathe spindle) with that sourced from the inner part of logs (<10 cm from the center of the veneer lathe spindle). LVL composed of the outer veneers was stronger than that composed of the inner veneers; 53% higher in modulus of elasticity, 65% higher in bending strength, and 26% higher in nominal shear strength. These results indicate that veneer sorting by radial location in logs is effective.","PeriodicalId":49800,"journal":{"name":"Mokuzai Gakkaishi","volume":" ","pages":""},"PeriodicalIF":0.3,"publicationDate":"2020-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45370940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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