Speed measurement on an isentropic compression experiment using digital image correlation

High pulsed power (HPP) drivers can be used to perform isentropic compression experiments (ICE) on materials in order to study their behavior under a different dynamic loading compared to shock. Photonic Doppler velocimetry (PDV) is used to measure the material velocity of the specimen subjected to the loading, but is limited to a few points of measurement, which can be a problem when studying heterogeneous materials or structural response of larger structures.

Digital image correlation (DIC) can help solve these problems by providing displacement, speed and strain measurement on the full surface of a specimen or a structure by using high-speed cameras and appropriate lighting.

DIC has been used to study the velocity field of the free-surface of the electrode used to perform the isentropic compression experiment. This field has been compared to several PDC measurements performed on the opposite electrode in order to assess the DIC measurement precision. In addition, another isentropic compression experiment has been performed on a carbon fiber reinforced plastic (CFRP) specimen, with comparison between DIC and PDV.