Measurement of Eggshell Thermal-mechanical Properties

Abstract

Three key engineering properties of eggshell material were measuredlinear thermal expansion coefficient, Youngs modulus, and shear modulus. The least-squares mean values of the linear thermal expansion coefficient of eggshell were 5.4 10-6 mm/mm- C and 7.3 10-6 mm/mm- C in the meridional and circumferential directions, respectively. the values of the linear thermal expansion coefficient of eggshell were significantly (p <0.001) affected by gage location and direction. The circumferential eggshell modulus of elasticity in the full ring compression test was 19.0 GPa with a standard error (SE) of 1.3 GPa. By applying a point load to the cantilevered eggshell strip, eggshell meridional modulus of elasticity was 208.8 (SE = 19.0) GPa. There was no significant difference (p = 0.16) in the values of eggshell modulus of elasticity for two different specific gravity eggs. However, eggshell modulus of elasticity values were significantly (p , 0.001) influenced by the location of the eggshell strips. In addition, the measured values of eggshell shear modulus were 5.8 (SE = 9.4) GPa and 90.8 (SE = 9.4) GPa in planes normal to the eggs circumferential and meridional directions, respectively. The values of the shear modulus of eggshell were significantly different (p <0.01) for high (=1.085) and low (<1.075) specific gravity eggs. In addition, there was a significant difference (p <0.001) between circumferential eggshell strip and meridional eggshell strip shear modulus values.