This lecture covers the material response of FCC, BCC, and HCP structures, focusing on the Taylor impact response and strain hardening behavior. It discusses the differences in yield stress, true stress, and true strain among different metal types, as well as the constitutive models used to describe their behavior. The lecture also delves into the Taylor cylinder-impact test, adiabatic shear bands, and their implications in various applications, such as military armor and fabrication processes.