Forming limit diagram, Perforated Al 8011, Limiting strain, Taguchi, Analysis of variance.
Sheet metal forming is a vital manufacturing process used in the automobile, aerospace, agriculture and architecture industries. The sheet metal is formed to various shapes to make useful components. The perforated sheets replace the solid sheet in some applications because of aesthetic appearance and low weight compared to solid sheet metal. The ability of the sheet metals to be formed into various shapes without failure is termed as formability. The formability of perforated sheet depends on chemistry of the material, the forming parameters, dimensions of the perforations and ligament width. In this paper, the forming limit diagram for perforated Al 8011 sheet of 1mm thickness has been evaluated and the influences of the diameters of perforations and ligament widths on the forming limit strains have been studied. The ligament width is the most influencing factor which has the percentage contribution of 70.04 and 72.55 in Tension-Compression, 69.65 in Plane strain and 51.49 and 71.84 in Tension-Tension conditions. This work gives reasonable forming limit plastic strains of the perforated sheets with various combinations of the diameters of perforations and ligament widths and also gives the prediction of these strains by varying it.
Keywords: Forming limit diagram, Perforated Al 8011, Limiting strain, Taguchi, Analysis of variance.