High pressure and shock loading experiments

High pressure and shock loading experiments for the characterization of materials under high loads and strain rates are being developed extensively since the middle of the last century. Experimental data are even today the indispensable basis for the development of material models describing the material behavior under extreme conditions like high-speed crash, impacts on aircrafts, bullet impacts, satellite, and meteoritic impacts. Beside plane-wave generators, plate impact experiments in single-stage and two-stage laboratory gas guns are the most widely adapted experimental technique to experimentally determine, e.g., shock velocity-particle velocity relations for a material. In these experiments, typically, the free surface velocity on the backside of the impacted sample is measured by a contact-free measurement with an interferometer (e.g., VISAR, velocity interferometer system for any reflector). The detailed analysis of the obtained velocity profile in high time resolution allows the derivation of material specific data such as the stress-volume relation along a Hugoniot curve and dynamic strength properties. This chapter describes the direct and the indirect (inverse, “sandwich” like) planar plate impact tests conducted with a gas gun, shows examples of free surface velocity time curves, and explains the determination of the material data from the experiments including an incremental analysis of the free surface signal.