Using Fracture Mechanics in Failure Analysis

Hardware subject to cyclic loading is usually designed using one of two methods, the classical SN curve or fracture mechanics. Due to preexisting flaws created during fabrication many SN curve designs will fail early because they became a fracture mechanics problem. The use of fracture mechanics can validate the early failure.

The failure of a large steel column that was subjected to cyclic loading over many years will be presented as an example. Fracture mechanics was employed and then compared to the fractographic features noted on the fracture surface.