Constitutive relation development through the FIRE test

Abstract

The importance of well-developed constitutive models for predicting deformation behavior of materials at high strain rates cannot be overstated. The study and development of these constitutive models is pertinent to several fields, yet the test methods utilized to probe this high strain-rate realm are limited in both number and standardization. In an effort to augment current high rate tests, new technologies have been leveraged to revive an old, under-utilized test method - the axisymmetric expanding ring. The combination of Photon Doppler Velocimetry (PDV) and one of several ring launch techniques allows the successful testing and instrumentation of samples loaded in tension without wave effects at strain rates exceeding 10^4 s^-1. Design and construction of the embodiment of this test at OSU, dubbed the Fully Instrumented Ring Expansion (FIRE) system, will be discussed. The key difficulties to implementation of the test are examined, along with our efforts to overcome them and preliminary results.