Monday  |  Salon 9  |  04:30 PM–04:50 PM

#16023, Thermomechanical Characterization of OFHC Copper for Model Calibration and Validation

Plastic deformation in metals can generate a large amount of energy, which is classically understood to be either stored in the material or dissipated, usually as heat. In this scenario, the dissipation of heat often leads to a local temperature rise, material softening, and strain localization-- in a feedback loop culminating in failure. Thermomechanical models seek to capture these coupled effects, which have value in many fields: e.g., high-speed machining, ballistics, sheet metal forming, additive manufacturing, accident/crash scenarios, and more.

In previous work, 304L-VAR stainless steel (SS) was characterized microstructurally and at a suite of temperatures, strain rates, and loading conditions, to gain a more complete understanding of thermomechanical coupling. A validation problem was developed to probe discrepancies between experimental data and model form error. Here, we extend the previous work to a second material, OFHC copper, which was selected as a material with (1) a strong literature precedent, (2) a reasonable difference in mechanical behavior/ material microstructure, and (3) a significant difference in thermal properties all with respect to 304L VAR. Copper tensile specimens were tested quasi-statically at strain rates up to 0.1 1/s and temperatures up to 300°C. Digital image correlation (DIC) and infrared (IR) thermography were used to capture the full-field thermomechanical response, and the thermal response was mapped to the DIC strain fields. Boundary conditions—both thermal and mechanical—were carefully measured, in order to be later applied in simulation. The development and application of a copper validation problem, appropriate for the change in material basis will be discussed, with an emphasis on focus points for simulation efforts.

ACKNOWLEDGEMENTS
Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA-0003525

Amanda Jones   Sandia National Laboratories
Thomas Ivanoff   Sandia National Laboratories
Matt Swanson   Sandia National Laboratories
Bonnie Antoun   Sandia National Laboratories
Edmundo Corona   Sandia National Laboratories
Brian Lester   Sandia National Laboratories