An analysis of defect size evolution

The progression of structural material towards failure may be thought of in terms of the evolution of the population of defects that it contains. An important statistical characteristic of the defect population is its size distribution. In the present paper we review the results of experimental observations of defect size evolution during damage accumulation due to different mechanisms and at different scales, i.e. creep bubbles, pores and cavities. We consider the probability density functions and cumulative density functions for defect size distributions, and identify several types of evolution observed. We also focus on the appearance of a 'tail' of large size defects, and discuss whether it could be used as an indicator of the transition to a new structural level or scale.