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Explosively driven fragmentation of ductile metals cylinders is a highly complex phenomenon, which is involved to many kinds of competition and coupling of fracture modes and was of interest to researchers. In this paper, the fragmentation experiments of TA2 industrial pure titanium cylindrical shell with varying charge were carried out. Through the analysis of macroscopic fracture and microscopic metallographic for the recovered fragments, the fracture mode and mechanism explosively fragmentation of TA2 metal are discussed. As the results shown that: (1) Though all of the TA2 alloy fragments failure with shear mode in explosive-driven cylinders expansion tests, the failure mechanisms of shear mode is different for tests with different explosion pressures. It is observed that the shear failure caused by the evolution of micro-voids in tests with relatively low pressure but controlled by multiple adiabatic shear localization in tests with relatively high pressure. (2) The microscopic metallography shows that the dynamic phase transition of α→β may occur during the high-speed deformation of the TA2. It is shown that the microstructure of the inner surface is converted to lath martensite with a specific orientation and the resulted grain size is apparently larger than the as-received. Thus, it is necessary to consider the influence of the dynamic phase transition of material under shock waves when analyze the fracture characteristics and mechanisms of external explosive experiments. This work can provide a significant reference to the analysis of multiple failure modes of cylinders under external explosion loading conditions.