EFFECT OF DEFECTS ON THE LIVES OF FRACTURE-CRITICAL AEROENGINE COMPONENTS

摘要

Current approved lifing methodologies for fracture-critical aeroengine components do not directly quantify the effect of defects on dysfunction lives. Given the overriding requirement for airworthiness, the practical consequences can include: unnecessary rejection of components with minor damage, risk of reduced safety when unexpected defects are found in service and relifing is attempted and delayed service entry of new materials with intrinsic defects. Towards development of a robust technical solution, two short-crack growth lifing models are presented. The first model can predict the form of life distributions at extremely remote probability levels. The second model can be used to make accurate predictions of the mean and scatter of short crack lives.