Abstract
The through fatigue-crack propagation rate for a centrally slitted low carbon steel plate has been determined. The rate, d(2a)/dN, is correlated with the stress intensity factor range, ΔK, as follows:
d(2a)/dN=C(ΔK)m
Strictly speaking, it appears that the larger the plate width (from 50mm to 200mm), the smaller the value of m, and that the higher the stress ratio (from 0.06 to 0.36), the larger the value of C. But, the plate thickness, slit size, stress wave, tensile/shear fracture mode transition behaviour and reduction of plate thickness resulting from general yielding do not affect the correlation. The fatigue life, Nf, is correlated with the initial apparent stress intensity factor range, ΔK0, as follows:
Nf=4.46×10-12(ΔK0)3.5
The predicted life from the rate is consistent with the correlation.