Fracture behaviors of explosively driven TA2 alloy cylinders under different loadings

The failure process of an explosively driven TA2 alloy cylinder is related with its material, structure, loading, and so on, with its fracture behavior shown in various ways. In this paper we investigated the mechanism underlying this failure under different explosive loadings using numerical and experimental methods. The results of the finite element analysis showed that, during the driven period, for the ideally homogeneous cylinder, the equivalent plastic strain effect in the inner zone of the cylinder's thick shell, where the secondary plastic zone was formed due to shock wave propagation, was always larger than that on the inner and outer surfaces; under higher blast loading, the cracks originated first in the secondary plastic zone during the driven period and propagated to the inner and outer surfaces in an angle of 45° or 135° to the radial; for lower blast loading, the shear cracks, which originated first in the inner surface, propagated to the outer surface in an angle of 45° or 135° to the radial during the free expanding period; and, although the cracks were all shear cracks, their failure mechanisms differed. The simulated results and experiments agreed pretty well. The phenomenon that cracks originated in the outer surface, as reported earlier concerning some related experiments, might have been affected by the specimens' geometrical and material defects, whose influence on the cylinder's explosion-induced failure needs to be studied further.