Comparison between different methods for the prediction of the fatigue limit of a member with a small crack

In the Kitagawa-Takahashi diagram and the corresponding analytical model by El Haddad et al., the fatigue limit of a cracked member is a monotonically decreasing function of the fatigue crack size. Based on data from fatigue tests by Schonbauer on plain and cracked members of 12 /0 Cr steel at R =-1, the present investigation shows that the Kitagawa-Takahashi-El Haddad 'short-crack' model yields predictions in good agreement with those by Frost and Murakami for different ranges of the crack size. The comparison with Frost's model is based on a surface through-crack, that with Murakami's \I area model on an embedded elliptical crack. Copyright (C) 2017 The Authors. Published by Elsevier B.V.