Mechanical behaviour of Ostrich’s eggshell at compression

Abstract

The deformation and fracture behaviour of Ostrich’s eggs at the static compression has been investigated. The mechanical properties of egg to compression were determined in terms of average rupture force, specific deformation and rupture energy along X and Z axes. Exact description of the eggshell counter shape has been used for the verification of a common accepted theory of the compression of bodies of convex form. The eggshell strength seems to be an unique function of the static stiffness. The greatest amount of force required to break the eggs was required when eggs were loaded along the X axis and the least compression force was required along the Z axis. The specific deformation and rupture energy required for the eggs tested was lower along the X axis than the Z axis. The highest measure of firmness in the eggs tested was found to be along their X axis. Young’s modulus of the elasticity, E, has been also evaluated. Its value is independent on the direction of the egg compression. The value of E is approximately two times higher that of the chicken eggs.

Keywords

• strength
• modulus of elasticity
• eggshell stiffness
• rupture force