Numerical and Experimental Estimation of Forces During Longitudinal Rolling Process of Shaft Formation

Abstract

The paper concerns the results of investigations on estimation of forces during longitudinal cold rolling of a shaft. It is difficult to determine theoretically the unit pressure and area of roller-shaft contact in the rolling process taking into consideration friction phenomenon, due to complexity of geometry of the deformation zone and complicated mechanism of deformation. In the shaft-roller contact area, one can distinguish two subregions: the area of contact of the shaft with the torus and the area of contact of the shaft with the cone. For both cases the analytical method of the determination of squeezing force has been presented. The experiments were carried out in order to determine the pressure force during the phase of squeezing on shafts formed by longitudinal cold rolling made of constructional unalloyed steels S235JR and C45. The experimental results were compared to numerical simulations performed using the MSC. MARC 2010 based on finite-element method (FEM). The FEM simulation was carried out for a real-size 3D model of the shaft and the tools. Numerical simulations were performed using the Updated Lagrange procedure and the material model taking into account strain hardening phenomenon. The numerical results have shown that on the longitudinal cross-section of the shaft, there are two characteristic regions with different distribution of effective strain. Furthermore, it has been found that the increase of radial force during squeezing phase is non-linear due to strain hardening of the shaft material and non-linear increase of the contact area.