Abstract
Resistance change measurements in ytterbium foils, encapsulated in a polymethylmethacrylate matrix and subjected to impact loading (to 25 kbars) and quasi-static triaxial loading (to 4 kbars), are presented. Two gauge orientations were examined. Residual resistance measurements were obtained for impact experiments. Both sets of experiments confirm the overall validity of the theoretical analysis described in Ref. 5. In particular, the crossover in resistance change-stress curves, predicted at low stresses, was measured. The present results show that gauge resistance measurements cannot always be uniquely related to a particular matrix stress component. Restricting the use of ytterbium foils to 20 kbars is inferred from the experimental results. The residual resistance data depend on both foil and matrix response. Finally, analysis of the resistance measurements, along the two orientations in the impact experiments, shows that polymethylmethacrylate retains significant material strength to 25 kbars.