NEW APPROACH OF EGGSHELL MECHANICAL PROPERTIES DETERMINATION

SEVERA, L., BUCHAR, J., VOTAVA, J.: New approach of eggshell mechanical properties determinantion. Acta univ. agric. et silvic. Mendel. Brun., 2010, LVIII, No. 1, pp. 161–166 The paper describes a new approach for determination of mechanical properties of hen’s eggshell. The suitability and applicability of a Berkovich indentation is discussed. The eggshells were tested in the area surrounding equator line. The deformation modes active during indentation have been examinined from the shape of load-displacement curves. According to measured dependencies, the eggshel shown an viscous-elastic deformation.The values of Young’s modulus E obtained from radial and tangential directions did not vary signifi cantly. This fact shows on isotropic nature of eggshell structure. It was found that values of E do not signifi cantly change neither around the cir cum feren ce of the equator. The values obtained within this research correspond to values reported in literature and obtained on macroscopic samples. Nanoindentation was found to be a precise and powerful tool, suitable for determining local variations of mechanical properties of eggshells. egg shell, modulus of elasticity, mechanical properties