Wall thickness variation during multi-pass spinning of large complicated shell

Using the 3D FEM model for the whole multi-pass spinning of a large complicated shell, including not only spinning process but also springback and annealing processes, established based on software ABAQUS/Explicit and Standard, the features of wall thickness and influence laws of process parameters on wall thickness during the spinning process have been obtained. The results show that wall thickness reduction undergoes shear deformation thinning and stretch thinning, the acutely thinning of wall thickness occurs at the ring behind the roller, then it transfers to the open end and its value decreases along the forming process. Wall thickness distributes unevenly along the generating line but evenly along the circumference directions of the work-piece. Unloading springback brings about unobvious variation on wall thickness. The increase of the friction factor to some extent can restrain the excessive thinning of wall thickness during the first pass spinning, thus make wall thickness distribute more evenly. But the effect of roller feed ratio on the wall thickness is contrary to the friction's effect. For the succeeding pass spinning processes, wall thickness decreases firstly then increases with the growing of the friction factor, but it decreases with the roller feed ratio. The results may be a helpful tool for determination and optimization of process parameters of multi-pass spinning process of the large complicated shell.