Fatigue Crack Paths

Abstract

Macroscopic aspects of fatigue crack paths, corresponding to the top two scales in Table 3.3, have been of industrial interest since the earliest fatigue investigations (see Sections 2.2.4 and 5.3.3.3). Microscopic aspects are of interest in the development of fatigue crack propagation resistant materials. Macroscopic aspects are emphasised in this chapter. Much current interest in fatigue crack paths is in the collection of data for the solution of specific engineering problems. The fatigue crack path in a critical structure in aerospace, automotive, offshore and other industries can determine whether a fatigue failure is benign or catastrophic (Grandt 2004). There is relatively little information on how to ensure that a fatigue crack path is benign. Knowledge of potential crack paths is also needed for the selection of appropriate non destructive testing procedures.