Virtual testing of Hopkinson's heterogeneous bars: Fondest hope and reality

At LMSSC, Cnam, Paris, June 2nd 2015, 11 a.m.

K.C. Park
Professor, Department of Aerospace Engineering Sciences, University of Colorado, Boulder, USA

A host of new engineering materials as well as new metamaterials are being developed and/or synthesized almost daily thanks to modern materials synthesis technology. However, before they can be considered for design applications, their constitutive properties have to be characterized. Traditional characterization process takes time, involving extensive laboratory testing. Numerical (or virtual) testing of new materials, if properly carried out, can substantially shorten the laboratory-conducted materials characterization process and offer insight to materials synthesis specialists as well in their new material development effort. For candidate materials to be used for systems undergoing dynamic loadings, the split Hopkinson bar test is the most widely used dynamic characterization procedure.

The present talk begins with requirements for numerically testing Hopkinson's heterogeneous bars. A foundational requirement is a robust wave capturing algorithm. The talk then concentrates on the development of new wave capturing algorithms that can trace waves propagating with different speeds. Numerical performance of the new algorithms is evaluated for 1D, 2D and 3D wave propagation problems. The talk concludes with an assessment of how close we are toward accepting virtual materials characterization in new materials development process.