Strain State in Metal Sheet Axisymmetric Stretching with Variable Initial Thickness: Numerical and Experimental Results

Featured Application This paper presents a stretching process of a metal sheet with a variable thickness. It gives products with better performances than that with constant thickness. This work presents a finite element model to analyze the distribution of the strains due to an axisymmetric stretching of a metal sheet. The sheet is characterized by a variable initial thickness. The resulting strain state is compared with that of a sheet with a constant initial thickness. The results of the present study allow asserting that the distribution of strains in the sheet can be controlled by setting opportunely the trend of the sheet initial thickness. In this way, it is possible to see that, starting from a sheet with variable initial thickness, a lighter final product is obtained, whose final thickness distribution is more uniform than that of the product obtained from a classic stretching process that requires a sheet with constant initial thickness. Encouraging results from an experimental activity carried out on an AA6060 aluminum alloy sheet, whose trend of initial thicknesses was prepared by removing material from a commercial sheet with a constant thickness, allow us to note the good agreement with what was theoretically highlighted.

Automated summary

This study presents a stretching process of a metal sheet with variable initial thickness and finite element model analysis. By controlling the trend of the sheet initial thickness, the distribution of strains in the sheet can be controlled, resulting in a lighter and more uniform final product compared to traditional processes with constant initial thickness. Experimentation on AA6060 aluminum alloy sheet confirms theoretical findings.