Weld metal ductility in aluminum tailor welded blanks

The objective of the research described in this article was to characterize and numerically describe the ductility of weld material in aluminum tailor welded blanks under uniaxial tension conditions. Aluminum tailor welded bl anks consist of multiple thickness and alloy sheet materials welded togethe r into a single, variable thickness blank. To evaluate the mechanical prope rties of the weld material in these tailor welded blanks, a series of tensi le specimens containing varying ratios of weld and monolithic material in t he gage area of the specimen were tested. These experimental results show t hat increasing the amount of weld in the cross-sectional area of the specim en decreases the ductility of the specimen and that the weld characteristic s have a pronounced impact on ductility. Using the experimental results and classical tensile instability and necking models, a numerical model was de veloped to describe the ductility of the weld metal. The model involves bas ic material properties and an initial imperfection level in both the weld a nd monolithic materials. The specimens studied were produced from 1- to 2-m m AA5182-O aluminum alloy sheet material welded into blanks using an autoge nous gas tungsten are welding process.