Monday  |  Salon 9  |  09:40 AM–10:00 AM

#15781, Conversion of Plastic Work into Heat in Dynamic Tensile Loading of 304L-VAR Stainless Steel

In structures undergoing plastic deformation, a significant portion of the plastic work applied to the material is converted to heat; the resulting temperature rise consequently influences the mechanical properties, including failure behavior. Reliable material modelling and simulation requires capturing this heat generation and the corresponding thermosoftening effect on material performance across a wide range of loading conditions, particularly at high strain rates where a nearly adiabatic condition applies. Evaluation of temperature rise due to plastic deformation under high-strain rate loading conditions is essential for determining the conversion ratio of plastic work into heat, known as the Taylor-Quinney coefficient. However, increasing the rate of deformation by orders of magnitude over quasi-static tests introduces a new set of diagnostic challenges, chief among which is accurate high-speed temperature measurement. In this study, the temperature rise in 304L stainless steel specimens subjected to dynamic tensile loading using a Kolsky tension bar was measured using two simultaneous infrared measurement techniques. An IR pyrometer is employed to measure the specimen temperature at a single point with high temporal resolution while a high-speed IR camera is used concurrently to obtain full field temperature distribution data at several instances throughout the loading process. Using these two instruments not only provides greater spatial and temporal resolution than could be achieved by any single instrument, but also proves the measurement credibility.

Sandia National Laboratories is a multimission 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-NA0003525. The views expressed in the article do not necessarily represent the views of the U.S. Department of Energy or the United States Government.

Colin Loeffler   Sandia National Laboratories
Amanda Jones   Sandia National Laboratories
Bo Song   Sandia National Laboratories