Studies on the chipboard : Part 1. Mechanical Properties

この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました

Evaluation of Fracture Toughness for Wood-Epoxy Adhesive System under External Shear Force

この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました。Fracture Toughness G_c of Wood-Epoxy adhesive system under external shear force was evaluated by employing the experimental compliance method based on the Griffith-Irwin fracture theory. Invariability of G_c with the different glue line length was tolerably recognized and the representative value of G_c for the above system was about 0.25 (cm・kg/cm^2) throughout the series of glue line thickness tested. Fracture mode and stress distribution were discussed with some helps of Finite Element Method

Dry-heat Degradation of Plywood-type Joint

この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました。In order to predict the service life of plywood heating floors, dry-heat exposure test of lauan plywood made with each of six type of typical wood adhesives was carried out at 50°, 70°, 100° and 150℃ for 250 days. Internal bond strength and location of failure of the exposed specimens were measured at selected intervals. Data were plotted as a function of the exposed time. Confidence limit was applied on the regression and the service life was calculated by extraporating the lower confidence limit curve to the half-strength. The apparent mechanism of dry-heat degradation of plywood in 150° and 100℃ seemed to differ from the lower temperature exposures. On 70° and 50℃, more conservative estimation was made by the kinetic method on the Arrhenius relationship. The result showed the detrimental effect of the acid catalyst on polyvinyl-acetate cross-linked and urea resin adhesives. Plywood specimens produced with melamine, phenol, phenol-resorcinol, and resorcinol resin adhesives showed excellent durability in dry-heat exposure at temperature normally found in service of floor heating

Studies on the drying of wood

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引張を受ける有節板のひずみ分布と破壊について

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Studies on the chipboard : Part 2. Swelling properties of chipboard

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Studies on the Mechanical Characteristics of the Orthotropic Plywood Shallow Shells (I) : Numerical Analysis

この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました。It is proved that the coefficients BH and Dij of the fundamental equations of the layered orthotropic shells can be calculated from the measured moduli of elasticity (E_, E_,…) and (E_, E_,…), respectively, according to the procedure shown in (3-17) and (3-18). And this is better than the calculation using the elastic constants of veneers, because the former include the effects of the adhesion and the pressing. It is very difficult to solve precisely the fundamental equations when the axes of elastic symmetry do not coincide with those of coordinates (B_≠0, B_≠0, D_≠0 or D_≠0). The authers attempted to solve them by the application of the finite difference method and succeeded in solving them with good accuracy of the approximation. The application to the layered orthotropic shells is more complicated than that to the isotropic shells, so the unique techniques were needed. The characteristics of the layered orthotropic shallow shells with roller-supported edges were made clear by this numerical analysis, that is to say, the influence of the following problems were analysed, and the results are shown in the figures and the tables; 1) the curvature, 2) the shape of the shells (H. P., Cyl., E. P.), 3) ratio of the side lengths, 4) the moduli of elasticity, 5) the direction of the elastic principal axis, 6) uniform pressure and a concentrated load

Numerical Analysis of Stress Distribution in the Prototype Test of the Wood Framed Bearing Wall

この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました。The stress distribution in the plywood bearing wall panel specimens being tested by different methods of the prototype test was analysed numerically by finite element method. The contour plot of shear stress and the principal stresses of the panel in three test methods were caluculated and discussed. In the diagonal compression test (method A) the stress concentration was observed near the loading and reacting points. This stress concentration became more conspiquous as the framing thickness decreased. In the simple racking test (method B) the stress concentration was most conspiquous and the shear stress distribution showed clearly the sudden discontinuity of stresses at the bolted point just under the loading point. Uniform stress distribution was found in the racking test with hold-down ties wellknown as ASTM type (method C). The load transmission abilities of these three test methods along the edges of the panels were in the order of C>B>A. While the test method C is the most pertinent method to provide the uniform shear in the specimen, the test method A is thought to be useful when used in tests including a great number of specimens such as the outdoor durability as it is very simple and handy to test

Fire Proofing Properties of Wood and Filter Paper treated with Cationic Melamine-Formaldehyde Condensation Products : Effect of Inorganic Acids on the Fire Proofing Efficiencies

この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました。The durable fire-retardants based on the colloidal solution of cationic aminotriazinealdehyde resin have been applied to HINOKI sliced veneer and filter paper. The treatment is accomplished by soaking samples through an aqueous solution of these resins, drying and curing at room temperatures. The effect of kind of acids and of varying ratio of fire retardant components in treating solution on the fire proofing efficiencies of HlNOKl sliced veneer and filter paper are discussed. Results are compared with those reported in previous paper and ammonium salts as fire retardant agents for wood, paper, fabrics and other combustible materials. Aminotriazine-aldehyde condensation products combined with strong acids such as phosphoric acid, hydrobromic acid, sulfuric acid and sulfamic acid imparted excellent fire resistance to wood and filter paper. Satisfactory fire proofing properties can be obtained in both HlNOKl sliced veneer and filter paper at resin add-on as low as about 10～15% with a few exceptions. Total amount of resin required becomes lower as the melamine/acid ratio is decreased

Studies on the Heat Conductin in Wood : The present study is a discussion on the results of investigations made hitherto by author on heat conduction in wood.

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