Abstract
This work is an extension of applying a previously developed fracture
mechanics cracking damage model to predict the fatigue lifetime of
un-notched round specimens made of a ferrite-pearlite 0.4C-70/30 carbon
steel in some cases of variable amplitude loading VAL. The model
simulates the collective behavior of growing short fatigue cracks
originating from the specimen surface roughness. Material grains of
different phases, sizes and strengths are randomly distributed over the
minimum circumference. Possible activities of surface cracks are
predicted against loading cycles. Relevant published experimental data
were utilized for comparison. The present predictions are in agreement
with the corresponding experimental results.