An analysis of the dynamic shear failure resistance of structural metals

The localization of shear deformation and the eventual rupture inside shear bands are analyzed experimentally. The shear failure resistance of several structural metals is compared. The materials studied are HY-80, HY-100, HSLA-80, 4340VAR, and Ti-6Al-4V. The evaluation of failure progression focuses on the evolution of both the stress-carrying capacities and material microstructures. Experiments show that despite its significantly stronger rate sensitivity, Ti-6Al-4V is more susceptible to shear localization and rupture compared with the steels, as demonstrated by its relatively early and precipitous loss of stress-carrying capacity. This observation is supported by measurements of the shear band and rupture lengths in specimens deformed to various stages of failure development. Among the steels, the martensitic microstructure of HY-100 seems to be responsible for its higher susceptibility to localization. While all the steels studied show Very similar dynamic constitutive responses, their significantly different shear failure behaviors suggest that macroscopic thermal-mechanical descriptions alone are not sufficient to account for the shear Failure in the form of combined localization of strain and the eventual rupture through the shear bands. Consequently, microstructural damage mechanisms should also be considered. (C) 1998 Elsevier Science Ltd. All rights reserved.