Introduction

Abstract

Experimental research in shock compression science is traditionally categorized into two distinct groups: real-time (time-resolved in-situ) shock experiments and end-state (recovery) shock experiments. Unlike time-resolved in-situ shock experiments, which are designed to acquire the velocity-time history of the material being investigated, shock recovery experiments were developed to augment the acquired time-resolved velocity history of the shock wave profile. The primary objective of a well-designed shock recovery experiment is to interrogate the residual structure-property relationships of a material, which has undergone a known uniaxial strain history under shock compression and then released back to ambient conditions without being subjected to rogue radial release waves. Shock recovery experiments are also routinely employed to study incipient spall failure and the characteristics of spall surfaces. Shock recovery experiments are difficult to execute and the acquired microstructural data are often quite complex to interpret. This is partly due to the extreme conditions (such as high stresses, elevated temperatures, high strain-rates, etc.) the material undergoes during shock compression and release but also because of the short time-scales involved (nanosecond shock rise time and few microseconds to completion). In addition to the complexities stated above, there is an existing knowledge gap between the ambient-state and the end-state of the material interrogated. That is, shock recovery experiments do not provide any information between the ambient-state and the end-state. This poses some serious challenges on the interpretation of the microstructural data. However, coupling multiscale modeling with results acquired from shock recovery experiments can help in closing this existing knowledge gap. Nevertheless, end-state shock recovery experiments are well suited to study end-state phenomena such as spall failure and the residual structure/mechanical properties of materials which have been shock compressed and released to ambient conditions.