Publications

Pulse shaping techniques for testing elastic-plastic materials with a split Hopkinson pressure bar

Frew, Danny J.; Forrestal, M.J.; Chen, W.

We present pulse shaping techniques to obtain compressive stress - strain data for elastic - plastic materials with a split Hopkinson pressure bar. The conventional split Hopkinson pressure bar apparatus is modified by placing a combination of copper and steel pulse shapers on the impact surface of the incident bar. After impact by the striker bar, the copper - steel pulse shaper deforms plastically and spreads the pulse in the incident bar so that the sample is nearly in dynamic stress equilibrium and has a nearly constant strain rate in the plastic response region. We present analytical models and data that show a broad range of incident strain pulses can be obtained by varying the pulse shaper geometry and striking velocity. For an application, we present compressive stress - strain data for 4340 Rc 43 steel. © 2005 Society for Experimental Mechanics.