Experimental Study of the Evolution of Plastic Anisotropy in 5754 Al-Mg Cold Rolled Sheets

Modeling the evolution of material anisotropy accurately is essential to sheet metal forming simulation and springback prediction. The objective of this preliminary study is to provide experimental data of the evolution of the preferred plastic anisotropy directions in 5754 Al-Mg cold rolled sheets under plane stress. This experimental analysis will be used as the base for the development and validation of a more realistic computational anisotropic elasto-plasticity model. Cold rolled sheets were prestrained by two different loading conditions. During the first loading, the initial anisotropy was enhanced by stretching the sheet along the rolling direction (RD). After the first prestrain, the second prestrain was applied at different angles measured from the RD. After the second prestrain, uniaxial dog-boned shaped specimens were cut at different angles from the RD for both as-received and prestrained sheets. Finally, these specimens were tested under tension. The results of different orientations were given, and rotation of the orthotropic axes was observed. Hill's quadratic yield criterion was used to fit the experimental data.