Forming limit curves of 1100 aluminum sheets and effects of strain path and sheet thickness on the curves

Abstract

The forming limit curves of 1100-O and -H24 aluminum sheets were determined. Effects of strain path and of sheet thickness on the curve for 1100-O aluminum sheet were investigated. Two types of strain paths were employed. Strain path I; equibiaxial straining followed by uniaxial straining, and strain path II; uniaxial straining followed by biaxial straining. The strain path I increases the limit strain in the range of the plane strain deformation compared with the monotonic straining, when the deformation in the first stage is small. The strain path II increases the limit strain more than the monotonic straining in the range of stretch-forming. The forming limit increases with the thickness of sheet.