Consumer willingness to pay for modern wooden structures: A comparison between China and Japan

Reliability analysis of compression strength of dimension lumber of Northeast China Larch

The collapse of Eucalyptus urophydis wood during conventional kiln drying prevents the widespread use of its wood products. This research aims to explore its collapse and recovery characteristics, as well as the effect of continuous and cyclic drying. The collapse was measured by total shrinkage, and cell deformation was observed at three critical points using scanning electron microscopy. The collapse and recovery were investigated by integrating the shrinkage curves and observing the cell micro-deformation. The results showed that the continuous drying rate was faster than that of cyclic drying, especially when the moisture content was below the fiber saturation point. Compared with relative humidity, the temperature had a greater effect on the tangential absolute dry shrinkage. Although cyclic drying decreased collapse, its effect was apparent only at low temperatures and was weak at high temperatures. The collapse recovery time was affected by temperature, and recovery occurred quickly at high temperatures, and the moisture content range was longer. In contrast to continuous drying, the high relative humidity period during cyclic drying led to earlier collapse recovery. The degree and trends of microscopic collapse were consistent with the macroscopic scanning measurements.

Study of the collapse and recovery of Eucalyptus urophydis during conventional kiln drying

Tension tests of metal-plate connected (MPC) joints for Chinese larch (Larix gmelinii (Rupr.) Rupr.) were conducted in four orientations. Load-deflection curves were obtained for each MPC jointed specimen. Ultimate tension load, translation stiffness, stiffness at large slip, and failure modes for each specimen were obtained. A Foschi 3-parameter model was found to fit the load-deflection curves very well. Wood grain, and MPC length and loading directions had significant effects on elastic deformation and stiffness at large slip of the MPC joints. Load parallel to the grain with MPC length parallel to load (AA) represented the highest elastic deformation, while load perpendicular to the grain and MPC parallel to load (AE) showed the lowest. Load perpendicular to grain with MPC length perpendicular to load (EE) presented the highest stiffness at large slip, AA the second, load parallel to grain-MPC length perpendicular to load (EA) the third, and AE the lowest. The translation stiffness and tension load showed similar trends in terms of the effect of test orientations. The ultimate tension load was reduced by 18.9% from AA to EA, 34.2% from AA to AE, and 36.8% from AA to EE. Multiple failure modes occurred at the MPC joint, including MPC shear failure, tooth withdrawal, and wood failure.

https://ojs.cnr.ncsu.edu/index.php/BioRes/article/download/BioRes_08_4_Guo_Tension_Chinese_Larch/2363

Tension Performance of Metal-Plate Connected Joints of Chinese Larch Dimension Lumber

This paper investigated the tensile behavior of metal-plate connected Dahurian larch (Larix gmelini (Rupr.) Rupr) lumber joints. Relationships between the ultimate load and metal-plate connector (MPC) length, width, and area were analyzed for AA loading (i.e. load parallel to the grain, MPC length parallel to the load direction) and EA loading (i.e. load parallel to the grain, MPC length orthogonal to the load direction). Failure modes were studies for both AA and AE loading conditions. It was found that the tensile strength of the joint increased as the size of the connector increased. Tooth withdrawals, MPC breakage and wood breakage were all failure modes observed for the AA loading case. However, tooth withdrawal was the only failure mode observed in the EA loading case.

/pdf/effect-of-metal-plate-connector-on-tension-properties-of-1aly64phtv.pdf

Effect of Metal-Plate Connector on Tension Properties of Metal-Plate Connected Dahurian Larch Lumber Joints

This paper reviewed the history of wood structural construction in China,its development and progresses made in the past ten years. It also analyzed the characteristics,distribution,and size of the wood structural construction industry. The domestic research needs on wood structural construction technology and standard for wood were summarized.

Wood Structural Construction Industry in China

The previous paper in this series summarized the developmental history,the industrial status,and the macroscopic characteristics of timber construction in China.The problems of China's wood construction industry,such as,a fragmentary industry chain,small scale enterprises,low-level technology and an underdeveloped social division were analyzed for this paper.The mutual management mode among ecosystem,timber construction and real estate and the development stratagem to capital operation,are presented.The author believes that the future of the Chinese wood structure industry should take into consideration new energy requirements,environmental impact,and acceptance of traditional culture.

Current and Future Status of Wood Structure in China(Part I)

The paper looks at the development of modern wood frame housing in China.It makes a detailed analysis the factors affecting the development of modern wood frame houses and,on the base,predicts the future development path for this new style of housing in China.

Future Development Path of Modern Wood Frame Housing in China

In this research,the vibration method was used to evaluate the mechanical properties of dahurian larch(Larix gmelini),a major softwood species that grows in the Northeastern China.The results showed a good relationship between bending strength and modulus of elasticity(MOE).The good correlation of dynamic(from the vibration test) and static MOE indicated that vibration could be used as an effective mechanical stress grading tool for larch lumber.Lumber was sorted into four grades: M22,M26,M30,and M35 using mechanical stress grading.The grades were equivalent to the European machine grade of C22,C26,C30,and C35,respectively.It was found that through mechanical grading;the graded lumber had a higher design value than the existing general design value of domestic larch according to GB 50005-2003.

Mechanical Stress Grading of Larch Dimension Lumber from Northeastern China

Metal-plate-connected(MPC) wood trusses for roofs and floors have been used in light-frame residential and commercial constructions for decades.Proper design and performance optimization of metal-plate connectors play an important role in manufacturing trusses and even throughout whole light frame structures.In this article,the basic principle of metal-plate connections,latest static and dynamic testing results,the failure mode and the impact factors on the connections were reviewed.Based on an extensive literature search,the authors provided some useful suggestions and guidance to develop and manufacture metal-plate connected wood truss in China.

Zhou Hai-bin

Papers

Wood Structural Construction Industry in China

Current and Future Status of Wood Structure in China(Part I)

Future Development Path of Modern Wood Frame Housing in China

Mechanical Stress Grading of Larch Dimension Lumber from Northeastern China

Review of Tests and Impact Factors of Metal-plate Connection