静的4点曲げ試験から得られた合板のヤング率およびポアソン比の測定値におよぼす試験体幅の影響

In this study, Young's modulus and Poisson's ratio of Lauan 5-ply wood as obtained by a static four-point bending test was examined by varying the width of the specimen. Additionally, three-dimensional finite element calculations were conducted to examine the influence of the width. A comparison of the experimental and numerical results revealed that the width of the plywood strip should be large enough to determine Poisson's ratio properly when the fiber direction of the surface veneer coincided with the length direction of the specimen. In contrast, this influence was not so significant when the fiber direction of the surface veneer coincided with the width direction of the specimen. Although Young's modulus can be determined properly independently from the width of the specimen, it is significantly influenced from the measurement method of the deflection. In particular, the Young's modulus obtained from the method determined as that in JIS Z2101-2009 was estimated to be extremely larger than those obtained from the other methods.