Effect of Loading Rate on Hen’s Eggshell Mechanics

The study is focused on analysis of mechanical behavior of hen’s eggshell expressed in terms of average rupture force and corresponding deformation. Some other physical properties such as mass, length, diameter, geometric mean diameter, surface area, sphericity, and volume were also evaluated. The egg samples were compressed along their X and Z-axes. Two different experimental methods were used: compression between two plates (loading rates 0.0167, 0.167, and 1.67 mm/s) and impact of a free-falling cylindrical bar (loading rates up to 17 mm/s). Surface displacement and surface velocity were measured using the laser-vibrometer. The increase in rupture force with loading rate was observed for loading in all direction (along main axes). Dependence of the rupture force on loading rate was quantified and described. The highest rupture force was obtained when the eggs were loaded along the X-axis. Compression along the Z-axis required the least compressive force to break the eggshells.