Amirkabir University of Technology Amirkabir Journal of Mechanical Engineering 2008-6032 48 4 2016 09 22 Determination Of Forming Limit Diageram Using Two Modified Finit Element Models Determination Of Forming Limit Diageram Using Two Modified Finit Element Models 379 388 664 10.22060/mej.2016.664 FA MOSTAFA HABIBI AHMAD GHAZANFARI AHMAD ASEMPOUR REZA NAGHDABADI RAMIN HASHEMI Journal Article 2015 06 24 In sheet forming processes, using Forming Limit Diagrams (FLDs) in study of formability and designi die is very important. One method to achieve the curves of FLDs that has validate and appropriate results is Marciniak–Kuczynski model. This model is a way to predict the local necking. In the present study, FLDs were achieved by imposing the theoretical Marciniak–Kuczynski model in two different finite element model and using Abaqus. In the first model, the theory of Marciniak–Kuczynski was imposed to finite element of Nakazima test and in second one (Flat), the theory of Marciniak–Kuczynski was simulated. The input data for these simulations was obtained from tension tests in three different directions. After comparing the results of Flat and Nakazima finite element model with empirical results, the FLD obtained from the finite element of Nakazima test was valid and less than 10 percent below the empirical FLD. Bending is the reason of difference between FLD obtained from Flat model and empirical one. In sheet forming processes, using Forming Limit Diagrams (FLDs) in study of formability and designi die is very important. One method to achieve the curves of FLDs that has validate and appropriate results is Marciniak–Kuczynski model. This model is a way to predict the local necking. In the present study, FLDs were achieved by imposing the theoretical Marciniak–Kuczynski model in two different finite element model and using Abaqus. In the first model, the theory of Marciniak–Kuczynski was imposed to finite element of Nakazima test and in second one (Flat), the theory of Marciniak–Kuczynski was simulated. The input data for these simulations was obtained from tension tests in three different directions. After comparing the results of Flat and Nakazima finite element model with empirical results, the FLD obtained from the finite element of Nakazima test was valid and less than 10 percent below the empirical FLD. Bending is the reason of difference between FLD obtained from Flat model and empirical one. https://mej.aut.ac.ir/article_664_2291d2ec3b3048d1a6f86c2c4591b7e0.pdf