Numerical investigation and Taguchi optimization of deformation behavior in dual-roller die-less spinning of aluminum alloys

Dual-roller die-less spinning is a flexible metal-forming process for manufacturing complex sheet-metal components in small batches without dedicated forming dies. However, the combined effects of process parameters on wall-thickness variation, plastic strain, stress distribution, geometric deviation, and forming force remain insufficiently understood. In this study, an explicit finite element model was developed using LS-DYNA to investigate the deformation behavior of AA-1060 aluminum sheets subjected to dual-roller die-less spinning. A Taguchi L9 orthogonal array was employed to evaluate the effects of initial blank thickness, forming depth, and mandrel speed on the principal forming responses. Analysis of variance (ANOVA) was additionally performed to quantify the relative contributions of the investigated process parameters to each response. The numerical and statistical results revealed response-dependent parameter sensitivities. Wall-thickness variation was primarily governed by forming depth and exhibited three stages: localized thickening near the tool-entry region, pronounced thinning within the primary deformation zone, and partial thickness recovery toward the blank edge. Equivalent plastic strain was also strongly influenced by forming depth, with localization in the mid-radius region where roller contact, bending, and stretching were most pronounced. In contrast, von Mises stress and maximum forming force were predominantly controlled by initial blank thickness, reflecting the greater resistance to deformation of thicker sheets. Geometric deviation was influenced by forming depth and blank thickness. The combined Taguchi and ANOVA analyses provided a systematic basis for comparing parameter effects across the investigated responses and identifying response-specific process settings. The findings highlight the trade-offs among thickness uniformity, dimensional accuracy, and forming-load reduction and support improved process control in dual-roller die-less spinning of aluminum sheets.