Failure Analysis

Failure analysis can identify a likely crack-initiation region by tracing fracture patterns and crack-propagation features back toward their origin. Investigators may examine fracture markings, crack branching, deformation, component geometry, stress concentrations, and microscopic features. Once the initiation region is located, the surrounding material, surface condition, manufacturing features, and service loads can be evaluated for conditions that may have contributed to crack formation.

Failed parts should be documented and preserved in their as-received condition before cutting, cleaning, sectioning, or otherwise altering potentially important evidence. Photographs, component orientation, mating fracture surfaces, deposits, markings, deformation, and surrounding parts may contain information that could be lost during destructive examination. A planned examination sequence allows visual and other nondestructive observations to be completed before sectioning, specimen preparation, or laboratory testing that permanently changes the evidence.

Failure analysis focuses on determining how a component or system failed by examining physical evidence, testing results, engineering data, and service history. It may identify technical causes or contributing conditions such as design deficiencies, material problems, manufacturing or installation issues, or service-related damage. Root cause analysis can extend the inquiry by examining why those conditions arose, including procedural, human, organizational, or systemic factors. The two approaches often overlap, and identifying a fracture, wear, corrosion, or other failure mechanism does not by itself establish the complete root cause.