A Priori Pulse Shaper Design for Constant-Strain-Rate Tests of Elastic-Brittle Materials
Pulse shaping techniques have been used for many years now in Kolsky bar testing of brittle materials. The use of pulse shapers allow the experimentalist to conduct high-strain-rate tests on brittle materials while ensuring that the sample will achieve a state of dynamic stress equilibrium before it fails, as well as to achieve a constant-strain-rate loading state for a large portion of the test. The process of choosing the appropriate pulse shaper system has typically been one of trail-and-error, sometimes requiring many experimental trails to achieve optimal results. Advances in analytic modeling of Kolsky bar tests now make it possible, in an a priori fashion, to design a pulse shaper system to produce a known constant-strain-rate experiment. This paper describes the approach of coupling these analytic models to an optimization technique to quickly find a pulse shaper system that will produce an experiment at a known constant-strain-rate. Experiments were conducted and the model predictions compared to resulting strain-rate histories for a G-10 material.
This work was partially supported by Sandia National Laboratories. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under Contract DE-AC04-94AL85000.
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