Adiabatic shear bands in α-titanium tube under external explosive loading

Abstract

The radial pressure explosive experiment is successfully used to investigate the formation of adiabatic shear bands (ASBs) in α-titanium (α-Ti) tube under external explosive loading. The ASBs initiate at the inner surface of α-Ti tube, and most of the shear bands are in spiral form along the cross-section of the tube towards counterclockwise direction. Tip of a shear band propagates along the surface of the maximum shear stress. Four patterns of ASBs such as bifurcation, collection, crossing and N-shape are observed. The developed shear bands are the preferred sites for nucleation, growth and coalescence of microvoids. The nucleation of microvoid is caused by the local hot spots and stress concentration in the shear bands. The coalescence of microvoids forms the crack within ASBs, and when the critical crack length is reached catastrophic fracture occurs.