Volume 17, Issue 4 (July 1989)
Low-Cycle Fatigue Analysis of Notched Members
Low-cycle fatigue crack initiation and propagation lives of notched members are investigated. By relating Nci(ΔJ/ψρ)β = Cn to the Coffin-Manson equation and correlating to test results, β and Cn are found to be functions of several parameters: cyclic stress-strain constants, geometry of notch (depth and curvature), and stress ratio. (ΔJ/σ′y) is chosen as a parameter for crack propagation in notched members. Fatigue crack initiation and propagation tests were conducted on notched plate specimens of different notch radii and stress ratios. Crack initiation life, crack propagation life, and total fatigue life are compared with the calculations. There are good correlations between the test results and the calculations.