THERMAL-MECHANICAL MODEL OF THE TUBE ELONGATION PROCESS IN DIESCHER MILL

The steady-state finite element approach is used to model the tube elo ngation process in Diescher's mill. The material is deformed between t wo rotating cone shaped rolls and a plug. The material is dragged by t he rolls, moves forward and rotates. The analysis of the process is pe rformed in the cylindrical coordinates. Tube ovalness is neglected. Th e material flowing in the circumferential direction is accounted for. The velocity field components in r,theta,z directions are discretized using parabolic shape functions. An iterative algorithm is employed fo r correction of the outer and inner free surfaces that determine the c ontrol volume. The material now and torsion, distribution of the effec tive strain and temperature are computed and analysed for the tube elo ngation process in Diescher's mill using a parabolic plug.