Wednesday  |  Conference Center B  |  09:40 AM–10:00 AM

#13423, Measuring Constitutive Law with Full Field Imaging

The characterization of mechanical behavior of materials has historically relied on simplified loading conditions which allow for assumptions such that stress can reasonably be inferred from measurable quantities. Two such pillars of mechanics are the uniaxial tensile test and the split Hopkinson (Kolsky) pressure bar (SHPB) experimental setups. Ultimately, in this new age of experimental mechanics, there is a need to define constitutive behavior of materials in the full phase space, which necessitates the implementation of full-field measurement for heterogeneous, multi-directional loading conditions. In this work, we propose a technique which leverages the power of the quantitative imaging technique of digital image correlation (DIC) to identify constitutive behavior for materials simply through manipulation of full field displacement measurements in dynamic experiments using SHPB. This technique is particularly powerful because it is indifferent to general assumptions required for conventional SHPB experiments, ultimately enabling one to test wide classes of materials, specimen geometries, and strain rates. Here, we will present the motivating theory, details and results of the technique itself, and validation of the constitutive behavior for a set of well-studied materials.

Barry Lawlor   California Institute of Technology
Guruswami Ravichandran   California Institute of Technology