Asymmetrical Sheet Rolling Research Articles

Analytical and experimental study on asymmetrical sheet rolling

An analytical model assuming constant shear friction between the rolls and sheet is proposed to explore the characteristics of asymmetrical cold and hot sheet rolling. In the hot sheet rolling process, the surface friction stress is assumed to be equal to the yield shear strength (i.e. τ = k). As the friction factor m is less than 1, the simulation for the cold rolling process can be conducted. To verify the validity of the proposed analytical model, a series of experiments on asymmetrical cold sheet rolling of aluminium are carried out. The total rolling force and the forward slip are measured. The proposed model is also used to estimate friction factor ( m) with the measured forward slip. With the estimated friction factors, the analytical rolling forces are calculated to compare with experimental data. Reasonable agreement is found. By this proposed analytical model, it is noted that a large amount of calculation time and computer expense are saved, and the characteristics of asymmetrical cold and hot sheet rolling are obtained easily and rapidly.

Analysis of Asymmetrical Sheet Rolling by Stream Function Method

A mathematical model for asymmetrical sheet rolling is proposed, using the stream function method and the upper bound theorem to investigate the plastic deformation behavior of the sheet at the roll gap. The curvature of the rolled product obtained under various rolling conditions of roll speed ratio, roll radius ratio, friction factor ratio, and inlet angle of the sheet at the entrance of the roll gap, are discussed systematically. The predicted curvature of the rolled product and rolling force are in good agreement with those of experimental measurements. Therefore, the proposed analytical approach is considered to be applicable for simulating asymmetrical sheet rolling.