In the 1995 Hyogoken Nanbu earthquake, steel structures failed in brittle failure modes that have been rarely observed before. Among them is brittle failure of a circular steel column after a severe elephant foot type buckling. These observations are followed by researches from various points of view. A convincing scenario is that an initial ductile fracture triggers eventual brittle crack propagation and it is in fact supported by some observations. The objective of this work is to pursue the possibility of a numerical analysis predicting initiation of such ductile cracks. Gurson type void damage plasticity model is modified to be valid for cyclic loading. These numerical results are compared to experimental observations.
