Abstract: Clad rolling is a rapid, efficient, and environmentally friendly method for producing composite plates, with significant potential for widespread application. The contact between the plate and the roll, as well as between plates, is a critical factor influencing the deformation and bonding strength of composite plates during the rolling process. To address the complex nonlinear contact issues inherent in clad rolling, a contact model was developed using the Mortar method to discretize the contact interfaces and the Lagrange multiplier method to enforce contact constraints. This model simulates the interactions between roll and plate, as well as between plates themselves. By interpolating the Lagrange multipliers with dual basis functions, the finite element stiffness matrix is simplified. Finally, a three-dimensional finite element simulation of the Cu/Al clad rolling process was conducted based on this contact model. The model has been verified to have high accuracy in predicting plate thickness and rolling force. The contact model can simulate the contact parameters on the contact interface. The results show that the contact interface between the aluminum plate and the roll, as well as the copper plate and the roll, is primarily characterized by sliding friction, whereas the contact interface between the copper plate and the aluminum plate is mainly characterized by stick friction. By simulating the clad rolling process under different reduction rates, the effects of the reduction rate on the neutral point and the cross shear zone were revealed, as well as the pattern of changes in the contact force at the plate interface with the reduction rate. The results indicate that as the reduction rate increases and the distance from the center of the plate decreases, the value of x_N/x_L decreases, and the increase in reduction rate causes a change in the direction of frictional forces on both sides of the cross shear zone. On the contact interface between the plates, the peak positions of pressure and frictional force gradually move away from the outlet as the reduction rate increases.

Key words: clad rolling, FEM, contact model, contact force, neutral point