Assessment of tool kinematics, mass scaling effects, and similarity theory in metal spinning simulation

Spinning processes are incremental sheet forming (ISF) operations that require computationally expensive numerical simulations due to the large number of increments required and complex tool-workpiece contact interactions. Similarity theory has demonstrated its applicability to spinning process modeling and, when combined with mass scaling, shows potential for increasing computational efficiency. This potential is investigated in this work through a metal spinning setup. A model of the process is developed using two process kinematics approaches: the classical one as used in experiments, and a modified version where the roller follows an enforced helical path while the mandrel remains fully constrained. Comparison of global and local outputs demonstrates very similar predictions for both kinematics. Analysis of mass scaled models using the modified kinematics reveals that higher scaling factors lead to interference from inertia effects and deteriorated contact treatment due to increased time increments. The choice of mass scaling factor depends on the trade-off between the computational time and the desired model accuracy. For the present spinning configuration, mass scaled similar models show no clear improvement in predicting local variables compared to mass scaled full-size models at equivalent computational times.