a) A three-point bending test is conducted on an aluminium oxide ceramic with a circular cross section. The ceramic has a radius of 4 mm. The specimen fractures at a load of 1100 N as measured by an Instron universal tester. If the distance between the supports was set to 5 cm, what would be the flexural strength of the ceramic?
b) Consider this same ceramic was then prepared with a square cross-section with edge-length of 1 cm and was subjected again to a three-point bending test. With a 5 cm separation in the supports still, at what load would you expect this specimen to break? Why ceramics are often tested in three-point bending instead of in tensile?