We’ve all attempted to break an egg by squeezing it with our hands and failed miserably. Like an arch under a bridge, the shape of an egg helps distribute the applied force across the entire surface. Cracking an egg with the edge of a pan is easy because the force is concentrated on one small section of shell. When force is applied more evenly eggs appear to be much stronger.
In an attempt to have a little fun we decided to try and test the strength of eggs (i.e. measure the compressive load required to break them). Using an eXpert 7600 Single Column Testing Machine paired with MTESTQuattro and a set of circular compression platens, we subjected two dozen eggs (one white, one brown) to messy battles against compression.
To distribute the compressive load across a larger area, a 1.5 x 1.5 in piece of foam was placed on top and below each egg. The eggs were tested both standing up and on their side. To try and minimize post-test cleaning time we placed the specimens in a small metal dish (this kinda worked).
The average load to break the eggs when standing up was 53 Lbs. On their side, an average of 90 Lbs was required. This makes sense because eggs are flatter on their side, which allows more of the platen/foam to contact the shell, helping distribute the force across a larger area.
More refined versions of this test could be useful in certain food and packaging applications. For example, farmers could measure the structural effects on eggs of organic and non-organic growing or different types of chicken feed. Packaging manufactures could compress the egg with different materials to develop better packaging.