Development of a Damped Bar Gauge for Long-Duration Stress-Pulse Recording

摘要

Various methods for reducing the amplitude of the stress pulse reflection from the end of a Hopkinson bar gauge have been evaluated with the intent of extending the useful recording time of the gauge without physically lengthening the dump bar. This work is the extension of a previously described acoustic technique into the multi-kilobar stress range. Preliminary success was obtained in laboratory testing of a 91 cm long attenuator of soft, steel-filled epoxy, precisely shaped to maintain a constant acoustic impedance along the bar. Keywords: Bar guage; Damped bar guage; Long duration stress measurements.