Young's modulus of the young rice plant

Abstract

Under the asumption that the leaf sheath of young rice plant (about 40 days' plant) is the tapered material of even density and isotropic elastic body with the lacuna, the Young's modulus of the leaf sheath was measured using each of tension, bending and vibration test methods. Area of the cross section of the leaf sheath contained about 37% lacuna, and the moment of inertia with lacuna was about 70% that of the full section. The value of Young's modulus of young rice plant was strongly dependent on the testing methods, and the value obtained by the tension test method was very small. It seemed that the main reason that for the discrepancies were occurence of the slippage between the cramp holding the load and the test piece. The value of Young's modulus obtained by bending method was smaller than the one obtained by the vibration method. Discarding the value of Young's modules obtained by the tension test method, it was about 25-50kg/mm². For the convenience of tests, the former two methods were preferable. Considering the organization of rice plant con sisting of the fiber and the matrix, its elastic property is anisotropic. Therefore new testing methodfor measurement of the elastic property of the rice plant may be needed.