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PDF : 07060242.pdf
title(En) :Shearing Modulus of Plywood and Hardboard Measured by the Panel Shear Test. I . Measuring of Shearing Modulus by the ASTM Method.
author(En) :Motoaki Okuma, Shitomo Mamada, Shinji Hirai
information :Mokuzai Gakkaishi 7(6), 242-246 (1961)
assort :Original Article
summary(En) :   The authors have studied the shearing modulus of lauan plywood and hardboard by the panel shear test. The test has been done conforming to the ASTM method. Test specimen is shown in Fig. 1. The experimental arrangement was prepared as shown in Figs. 2 and 3. The physical properties and Young's moduli of test specimens are shown in Table 1. The results obtained are summarized as follows.
   1) As shown in Fig. 5, the load-strain curve varies considerably according to the location of the wire strain gauge on the test board. Wire strain gauges pasted parallel to the direction of the load indicate compressive strains and gauges perpendicular to the direction of the load indicate tensile strains.
   2) As shown in Fig. 6, the strain in 45° to the direction of the load is so small comparing with the strain perpendicular to the direction of the load that it may be negligible.
   3) From the theory of isotropic plate, the following equation is introduced.
          
here,
        fs : shearing stress (kg/cm2),  ε :   strain in diagonal direction of specimen,
        P  : total load (kg),                       G :   shearing modulus (kg/cm2),
        Ls : length of the side of specimen (cm),   t :   thickness of specimen (cm).
   We obtained the following equation.
          
   4) Shearing moduli calculated from the test results are shown in Table 2. The value of shearing modulus of hardboard is unexpectedly large and shows much dispersions.
   5) The load-strain curve of hardboard is divided into two straight lines as shown in Figs. 7 and 8, therefore some different values of shearing modulus is obtained according to curve divisions.