The effect of the interaction of multiple flaws on ductile fracture is studied numerically by Gurson’s constitutive equation. Based on experimental results, two parallel flaw and three parallel flaw problems are simulated. Flaw coalescence does not occur in some problems but does occur in other cases. In all cases, ductile fracture processes are obtained, and the results are compared with the experimental results. The fracture pattern and load-displacement curves agree well with the experimental results. The void growth term is found to be dominant for the coalescence of flaws. The slant flaw problem and the nonuniform length flaw problem are simulated and an evaluation method for the multiple flaws problem is discussed.

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