Factors affecting the non‐destructive and destructive methods of measuring egg shell strength by the quasi‐static compression test1

Abstract

Precise measurements of shell deformation and fracture force were made to examine the destructive and non-destructive quasi-static compression tests of egg shell strength. Prediction of shell strength from shell deformation was not greatly improved by combining egg length, diameter and shell thickness with shell deformation. Cracks changed the deformation by an average of 8% providing the crack was not near the points where force was applied. Use of a hole or rubber on the lower compression surface to stabilize the egg increased the force required to fracture the shell at the upper flat surface. Shell deformation and its correlation with strength was also reduced. The fracture force predicted by a non-destructive deformation measurement was greatly affected by the force applied. The optimum test force was 1 kg at the equator.