Full-Cross-Section Deformation Characterization of Cu/Al Bimetallic Tubes Under Rotary-Draw-Bending Based on Physics-Driven B-Spline Curves Fitting

It is difficult to detect the inner layer of the bimetallic tube and to describe its full-cross-section deformation, which affects its verification and utility negatively. To tackle this issue, a novel theory is proposed for fitting the full-cross-section deformation characterization of Cu/Al bimetallic tubes under Rotary-Draw-Bending. The cross-section profiles on the bending outside are fitted through the physics-driven B-spline curves, whose interlaminar shape inheritance is implemented by the same position angle of the corresponding control vertices. The cross-section profiles on the bending inside are fitted through the regular curves considering the elongation percentage. The comparison between the theoretical profiles and the experimental profiles shows remarkable agreement. Additionally, the effect of the various wall-thickness and the wall-thickness ratio on the full-cross-section deformation is studied