Three-Dimensional Finite-Element Analysis of High-Speed (Millisecond) Measurements

Millisecond pulse heating has become an established method to obtain accurate thermophysical property data for solid metallic materials at high temperatures. This technique is based on rapid resistive heating of a tubular- or rod-shaped specimen by an electrical current and simultaneously measuring the pertinent quantities with, at least, millisecond resolution. The temperature development during heating and subsequent cooling is usually measured by a high-speed pyrometer. For the case of a tubular specimen, the pyrometer is focused on a blackbody hole in the ceInter part of the specimen. A three-dimensional finite-element analysis was used to investigate the limitations of the method used. A commercial program (ANSYS) was used for a highly nonlinear finite-element analysis taking into account temperaturedependent material properties as well as heat transport by radiation. Results of the simulated temperature and current density distributions are preseInted and discussed