A High-Speed Photographic Study of the Rapid Deformation of Metal Annuli: Comparison of Theory with Experiment

摘要

It is very important to know what friction correction to make to stress-strain curves obtained in compression so that constitutive models of metals can be accurately checked. However, it recently became apparent that standard analytical models commonly used to correct for friction in the split Hopkinson pressure bar have some serious errors. In this paper, we report a novel method of determining the friction coefficient for the case of axial compressive dynamic deformation of annuli. The method combines numerical modelling with high-speed photography and has been validated using Rolled Homogeneous Armour (RHA) steel.