The accuracy of simulations for modeling of machining processes is often limited due to insufficient knowledge of the material properties during machining, which can involve strain rates on the order of 104 per second or higher, plus rapid material heating. By adapting a traditional Kolsky bar (split-Hopkinson pressure bar) to an existing electrical-heating materials test facility, we have developed at the National Institute of Standards and Technology (NIST) the capability to provide high strain-rate, stress-strain data for rapidly preheated metal samples. By electrically heating the sample in ~500 ms immediately before the mechanical impact, we limit possible microstructural changes in the sample, and a stress-strain relationship can be determined at different temperatures for various test materials. The paper will discuss the design and construction of this new Kolsky bar facility and present preliminary data obtained from pulse heated dynamic tests.
Proceedings Title: Proceedings of Society for Experimental Mechanics, Society of Experimental Mechanics Annual Meeting
Conference Dates: June 2-4, 2003
Conference Location: Charlotte, NC
Conference Title: Society of Experimental Mechanics Annual Meeting
Pub Type: Conferences
dynamic material properties, Kolsky Bar, machining simulation