Effect of Equal Biaxial Pre-Strain on Forming Limit Diagram of AA5083

Abstract

In this work, the effect of equal biaxial pre‐strain on the forming limit curve (FLC) of 5083 aluminum alloy has been investigated. For this purpose, in the first stage, square blanks with dimensions of 200 mm in each length were cut from the original sheet and stretched by a spherical punch to the specified heights. Then, specimens were prepared by cutting the pre‐strained blanks with the longitudinal axis parallel and perpendicular to the rolling direction. In the second stage, the specimens were tested by the out‐of‐plane test method to determine the forming limit diagram (FLD) according to the ISO 12004. Furthermore, forming limit stress diagram (FLSD) was determined by using Hill’s quadratic yield function. The results showed that the equal biaxial pre‐straining decreased and shifted the FLC to the right hand side of the diagram. However, it had not any effect on the forming limit stress curves.