Volume 30, Issue 2 (March 2002)
Fatigue Crack Growth in Cantilever Bending Under Displacement Control
Fatigue crack growth (FCG) behavior of two martensitic steel grades was investigated using a single edge-notched bend specimen fixed beyond the notched section in cantilever bending under displacement control. This task was made possible by a new and original testing methodology developed on the basis of finite element analyses to define valid boundary conditions and the corresponding stress intensity factor K-expression for the test specimen. The behavior has been described including the nearthreshold zone and the second zone of relatively high FCG rates. Results for the two steel grades were found to correspond well with the empirical models reported in the literature. This confirms the validity of the methodology proposed in the present paper, which can be attributed to: (1) the accurate K-expression for the test specimen, (2) the proper definition of the boundary conditions adopted during testing, and (3) the validity of the adopted boundary conditions.