Resilience is a measurement of a material’s fragility, determined by the work needed to dynamically break the sample, compared against a vertical sample profile.
The Charpy test method
This method involves resilient bending of a cuboid sample with or without a notch, supported by two props and determination of work needed to break it. The notch is used to concentrate strains at a particular point on the sample under test. Resilience determines the work needed to dynamically break a sample, compared to 1 m2 of vertical sample profile (in the case of resilience with a notch, then against the profile at the notch’s location).
The Izod test method
The Izod method differs from the Charpy method in terms of the means of sample mounting, measurements performed and the speed of hammer pendulum impact. The method tests only samples with notches. The sample is mounted vertically, with one end in the hammer base mount and is broken with a cylindrical bladed pendulum at a specified distance from the edge of the mount.