Comparison of new analytical and numerical approaches to model the three-roll-push-bending process

摘要

Freeform bent tubes can be produced with the highly flexible three-roll-push-bending. The process has been fundamentally investigated in recent research by numerical simulation using shell or volume elements. However, because of the large aspect ratio of tube length to wall thickness, computation time required is high. This prohibits the integration in analysis routines to predict the resulting geometry online. In this contribution, the basics of two new approaches are presented to compute the resulting bending radius of two-dimensional freeform bends requiring significantly less computation time. The first approach is based on an analytically derived moment-curvature relationship considering realistic flow behaviour. In the second one, a numerical method is developed using beam elements. The results are compared to experimental data and to numerical results using shell elements for steel and aluminium tubes.