Similarities of Fatigue Failures in Various Materials

A California materials expert has performed hundreds of materials failure analysis on a wide variety of materials. Surprisingly fatigue failures have the same appearance regardless of type of material. Above are three examples of fatigue. Upper left is a sample of a rubber fatigue failure. This is very similar in appearance to the CPVC pipe plastic fatigue failure (center) and the metal fatigue failure (right). All these fatigue failures start at one point and "progressively" spread out leaving redily distinguishable fatigue "beach marks" indicating the direction of travel.