SENSITIVITIES WHEN MODELING ELECTRICALLY-ASSISTED FORMING

摘要

Recent research by the authors has resulted in the conception of several methods of accounting for direct electrical effects during an Electrically-Assisted Manufacturing (EAM) process, where electricity is applied to a conductive workpiece to enhance its formability characteristics. The modeling and analysis strategy accounts for both mechanical effects and heat transfer effects due to the applied electrical power. This work presents a sensitivity analysis and explanation of several key material and process inputs during an Electrically-Assisted Forming (EAF) test on Stainless Steel 304 and Titanium Grades 2 and 5 specimens. First, the effect that the specific heat (C_p) value has on the model will be discussed and compared with another lightweight material. Second, the significance of all three heat transfer modes (conduction, convection, and radiation) will be noted, and any possible simplifications to the existing heat transfer model will be highlighted. Third, the general electroplastic effect coefficient (EEC) profile shape for the Stainless Steel 304 material will be compared to that of Titanium alloys. Fourth, a frequency analysis will be done on the data taken during the experiments, by way of a Fast Fourier Transform (FFT), and the variation of frequency response with the electric input is studied. Overall, this work provides insight into several factors affecting a material's EEC profile, and also compares resulting EEC profiles of various materials.