Wire probe for the continuous recording of large deformations during the dynamic loading of a structure

The probe described in the paper is a thin (diameter of 0.1 mm) Nichrome wire. It was coiled about metal pipe and ring specimens and covered with a thin layer of epoxy resin and used to record the time dependence of the mean axisymmetric deformation of these structures during explosive loading. A time-stabilized current of 20-micro-amps was passed through the wire. The aim of the experiment was to measure the periodic voltage drop in the wire coiled about a steel tube and a ring of annealed aluminum alloy and to calculate the time dependence of deformations on the basis of these data. The effectiveness of the wire probe is compared with that of schlieren photography in measuring explosive load deformations.