INVESTIGATION OF VARIATION OF TRIAXIALTY AND LODE ANGLE PARAMETER VALUES IN SHEET METAL FORMING PROCESSES

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2022-8-29
Güzelderen, Tolunay
The aim of this study is to find out the relations of stress triaxiality and Lode angle parameter with the deformation characteristics of deep drawing process. For this purpose, deep drawing process is analyzed numerically by using different yield criteria, ductile criteria and hardening models for two different sheet materials. The simulations are carried out by using the finite element method. Square and cylindrical cups made of Al-2024 aluminum and AISI 304 steel are formed. Von Mises and Hill48 yield criteria are applied with the Johnson-Cook and the Hosford Coulomb ductile criteria. For hardening Johnson-Cook model and direct implementation of the plastic stress-plastic strain relations are used. The results are presented in terms of effective plastic strain, triaxiality and Lode parameter distributions within the deformed blank. The tensile, compressive and shear nature of the deformation is evaluated by referring the corresponding triaxiality and Lode angle parameter values. Triaxiality and Lode angle parameter values are also considered the verify the type of the fracture. For the fractured points in the deformed cups the variation of triaxiality and Lode angle parameter values with respect to equivalent plastic strain are presented by considering the two different ductile fracture criteria.

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Citation Formats
T. Güzelderen, “INVESTIGATION OF VARIATION OF TRIAXIALTY AND LODE ANGLE PARAMETER VALUES IN SHEET METAL FORMING PROCESSES,” M.S. - Master of Science, Middle East Technical University, 2022.