Piezoresistance response of ytterbium under static and dynamic loading

Resistance change measurements in ytterbium foils (encapsulated in a PMMA matric) subjected to quasi-static triaxial (to 0.4 GPa) and shock wave loading (to 1.2 GPa) have been obtained. The use of a solid matrix in the quasi-static experiments is a new feature and ensures consistent comparisons between the two types of experiments. Two sets of gauge orientations, with respect to the matrix stresses, were examined in each type of experiment. Experimental results were analyzed in terms of the recently developed theoretical analysis. Both sets of experimental data confirm the general theoretical framework; an important difference between the static and dynamic measurements can be explained on the basis of the inclusion analysis. Results from these data have pointed out areas in need of refinement in the theoretical work and provided calibration data for lateral stress measurement in uniaxial strain experiments. These necessary theoretical developments, along with a determination of the piezoresistive coefficients, will be examined in the future.