Challenges in predicting crack growth in structures operating in extreme environments

Abstract

In creep-brittle materials, where there is competition between the evolution of crack tip stress fields due to time-dependent deformation and due to environment enhanced crack growth under sustained and cyclic loading, there are no unifying concepts that are currently available to characterize crack growth. This is a major gap in technology that currently exists and prevents the use of time-dependent fracture mechanics approach to an important class of high temperature materials such as Ni base alloys, directionally solidified (DS) materials, and single crystal (SX) materials. This paper critically reviews the promising approaches, and the needs for filling this technology gap. Recommendations for future work are made.