Numerical and experimental study of the cold expansion process in 7085 plate using a modified split sleeve

In this work, the split sleeve cold expansion process is studied numerically and experimentally. The finite element (FE) simulations show that a strain concentration occurs in the material near the sleeve split. The results are not very sensitive to macroscopic plastic anisotropy. This means that cracking during this process is influenced more by the sleeve geometry than by the material properties. It is also shown numerically that a different sleeve design can reduce the strain concentration drastically. Therefore, this sleeve design is investigated experimentally on a 7085-T7651 aerospace aluminum alloy plate. Although the new design is not optimized, experimental evidence shows that it can significantly reduce cracking near a sleeve split.