FEM analyses were performed for stainless steel plates with multiple through-wall cracks. The geometry of the test specimens and the initial cracks were matched to those of a separately performed fatigue crack growth tests. The analytical results showed that the two cracks grew parallel to each other, then changed direction and finally coalesced. It is qualitatively agreement with experimental results. In addition, other simulation results, with lower magnitude of cyclic stress, showed that different propagation passes and different phenomena of coalesce. From the von Mises stress distribution of each analysis, it was found that the stress exceeded the yield stress when the crack tips were close to each other. It was suggested that the specimen with cracks were ultimately collapsed by plastic collapse rather than fatigue failure.
Miyachi et al. (Wed,) studied this question.