Effects of Temperature and Strain Rate on the Forming Limit Curves of AA5086 Sheet

Abstract During the warming forming process of aluminum alloys, both temperature and strain rate have significant influences on sheet formability. However, current research regarding the effects of temperature and strain rate on the forming limit curves of aluminum alloys is still lacking. Due to the difficulty in carrying out the experiments for obtaining forming limit curves under dynamic forming conditions at elevated temperature, in this work, the method is proposed to investigate these effects by combining a modified Voce constitutive model (Lin-Voce model) with the numerical simulation of Marciniak test. On the basis of experimental data obtained by the tensile tests, the material parameters of Lin-Voce model are identified by the inverse analysis technique. Then, the proposed Lin-Voce model is verified by comparing numerical and experimental results obtained by Marciniak test. Finally, the numerical simulation of Marciniak test is carried out at different temperatures (100, 200 and 300 °C) and punch speeds (10, 750 and 1000 mm/s), and the effects of temperature and strain rate on the forming limit curves of AA5086 are investigated and discussed.