Proposal of a numerical model using the finite element analysis of pilger rolling for improvement of computation precision and efficiency

Abstract

This paper presents a new numerical analysis method for cold pilger rolling which leads to compatible improvement of analysis accuracy and shortening calculation time. In pilger rolling, a raw tube is rolled by dozens of "shots", which is repetitive reciprocating movement of caliber rolls. Previous studies carried out only one shot analysis for shortening calculation time. However, these studies cannot consider an accumulated plastic strain by the dozens of "shots". The proposed method is composed of two models. In the first preliminary model, the accumulated plastic strain is evaluated based on the strain increment between the two continuous shots. The second main model is given the pre-strain calculated by the preliminary model, and analyses of shots are conducted until tool load becomes stable. This paper clarified the number of shots until stable tool load was obtained in the proposed model. In addition, the proposed model can improve analysis accuracy of the rolling load while shortening calculation time by 60 %, compared with the conventional models of dozen of shots.