THERMOMECHANICAL MODELIG AND ANALYSIS OF THE THREAD ROLLING PROCESS WITH ELECTROCONTACT HEATING

The work presents application of the variational and finite element methods for the modelling and analysis of the physical phenomena in the thread rolling operation with electric current. This process is considered as geometrical, physical and thermal nonlinear boundary initial problem with surface (as a result of friction and the flow of electrical current by contact zone) and volume heat source (as a result of visco-plastic deformation and the flow of electrical current), which move with the tool. But the boundary conditions for displacement and temperature are not known in the contact zone. Physical and mathematical model of the process of thread rolling and an thermo-elastic (for reversible zone) and thermo-visco-plastic (for non reversible zone) material model have been elaborated. The model takes into account the strain, strain rate, temperature histories of the material and the impact of visco-plastic deformation of the body on temperature rise.