Amirkabir University of Technology Amirkabir Journal of Mechanical Engineering 2008-6032 52 3 2018 11 20 Theoretical Analysis of the Temperature and Strain Rate Effects on the Forming Limit Diagram of AA3104 Theoretical Analysis of the Temperature and Strain Rate Effects on the Forming Limit Diagram of AA3104 555 570 3133 10.22060/mej.2018.14407.5848 FA Seyedeh Maryam Mirfalah Nasiri Ph.D. Student of Mechanical Engineering/ Guilan University Ali Basti Ramin Hashemi Iran University of Science and Technology Aboulfazl Darvizeh Department of Mechanical Engineering, Bandar Anzali Branch Journal Article 2018 05 04 Forming limit diagram is one of the most applicable methods for prediction of the plastic instability in sheet metal forming in which is very much affected by the influences of strain rate and temperature. In this paper, taking the temperature and strain rate effects into account, the true stress-true strain and forming limit curves of AA3104 aluminum alloy are analytically investigated by considering the Marciniak-Kuckzynski method and Johnson-cook model. The obtained theoretical results based on the Ludwik model are validated with the experimental ones. Furthermore, according to the stress[1]strain curves based on the Ludwik equation, Johnson-Cook coefficients are calculated for sheet metal AA3104. The stress-strain respond and forming limit diagram are produced over a range of strain rates (10-5 to 10-3 S-1) and temperatures (50-400 o C ). The results show that the stress-strain curve decreases with increasing temperature and increases with increasing strain rate. Also the forming limit diagram increases with increasing temperature and decreases with increasing the strain rate. The results exhibit a positive sensitivity of the temperature on the limit strain due to the thermal softening and the negative strain rate sensitivity on the forming limit diagram AA3104 due to the behavior of crystallographic structure of the material. Forming limit diagram is one of the most applicable methods for prediction of the plastic instability in sheet metal forming in which is very much affected by the influences of strain rate and temperature. In this paper, taking the temperature and strain rate effects into account, the true stress-true strain and forming limit curves of AA3104 aluminum alloy are analytically investigated by considering the Marciniak-Kuckzynski method and Johnson-cook model. The obtained theoretical results based on the Ludwik model are validated with the experimental ones. Furthermore, according to the stress[1]strain curves based on the Ludwik equation, Johnson-Cook coefficients are calculated for sheet metal AA3104. The stress-strain respond and forming limit diagram are produced over a range of strain rates (10-5 to 10-3 S-1) and temperatures (50-400 o C ). The results show that the stress-strain curve decreases with increasing temperature and increases with increasing strain rate. Also the forming limit diagram increases with increasing temperature and decreases with increasing the strain rate. The results exhibit a positive sensitivity of the temperature on the limit strain due to the thermal softening and the negative strain rate sensitivity on the forming limit diagram AA3104 due to the behavior of crystallographic structure of the material. https://mej.aut.ac.ir/article_3133_7221e5c8ec6b08ef6d3f9ff3ce6eb1d1.pdf