A statistical approach in the FEM simulation analysis of geometrical product specification during the cold tube drawing process

The cold drawing process produces high-quality tubes with precise dimensions, good surface quality, and higher strength due to cold forming. The tube drawing is used to reduce the cross section of the produced tubes. Depending on the reduction size, the outer diameter and wall thickness of the final tube changes. Due to the fact that cold drawing of tubes is mostly the last operation of production, it is necessary to pay attention to the process parameters and geometry of the forming tools. This paper presents a statistical evaluation of the influence of the wall thickness of the pre-tube, die diameter, and pre-tube diameter on the measured responses, which were the outer diameter and wall thickness of final tube, after the FEM simulations of the drawing process. For these purposes, a factorial design with three input factors was implemented. The goal of using the simulations was also to investigate whether the single-pass type of tube drawing would guarantee useful statistical results that could lead to significant time and cost reductions. The FEM simulations were executed using DEFORM software of Scientific Forming Technologies Corporation with Design of Experiment application module of this software. A factorial design of experiment has been processed in Minitab v. 17 software. The results show that most of the factors significantly influenced the response variables.