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Influence of constitutive and process parameters on the cylindrical cup deep drawing predictions for AA2090-T3 sheet

Constitutive modelling of the anisotropic plastic behaviour of the sheet material is of the great importance in the design and analysis of the forming processes intended for these materials. In this article influence of the constitutive parameters, directional dependences of the tensile and compressive yield stresses and Lankford parameters, on the cylindrical cup deep drawing predictions for AA2090-T3 sheet is analyzed. Finite element simulations of the cup drawing process are performed with the finite element program ADINA upgraded with the several orthotropic elasto-plastic constitutive formulations that are adjusted to the different sets of the material data. The analyzed constitutive formulations are based on isotropic hardening, associated or non-associated flow rule and symmetric orthotropic Hill (1948) stress function. In order to evaluate the impact of the strenght diffential effect on the final cup predictions, an investigation is carried out with a recently proposed constitutive formulation based on non-associated flow rule and asymmetric orthotropic yield function derived by extending the original orthotropic Hill (1948) equivalent stress term with a linear combination of the normal stress components. Furthermore, influence of the blankholder force and friction coefficient on the cup earing profile is assessed.

orthotropic material; constitutive modeling; yielding asymmetry; finite element method; cylindrical cup deep drawing; earing

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