Synergistic Optimization of Shape-Force and Dynamic Coupling Effect in Bending Roll Systems During accelerated rolling

During the accelerated production process of continuous cold rolling mills, transient speed transitions induce dynamic imbalances in the rolling force field, leading to critical strip quality issues such as thickness fluctuations and shape defects (e.g., edge waves, center waves). These defects severely restrict the production efficiency and product quality of high-end cold-rolled strips. To address this challenge, this study establishes a three-dimensional elastoplastic finite element model of a six-roll cold rolling mill on the ABAQUS platform, systematically investigating the dynamic coupling mechanisms between work roll bending (WRB) and intermediate roll bending (IRB) forces on strip thickness distribution, flatness evolution, cross-sectional crown, and rolling force field. A composite control strategy integrating dynamic bending force compensation and tension cooperative control is proposed, supported by a segmented speed interval optimization model.Key findings reveal that increasing WRB shifts strip thickness distribution from a "thick center, thin edges" profile to a "thin center, thick edges" configuration, effectively suppressing secondary wave defects. Conversely, IRB enhances thickness uniformity but exhibits limited control over quaternary wave defects. Both bending forces stabilize the rolling force distribution and inter-roll pressure, with WRB demonstrating superior secondary crown reduction and IRB optimizing edge-to-center thickness gradients. Furthermore, segmented speed interval optimization combined with dynamic compensation reduces edge wave defects by 32% during acceleration and improves thickness uniformity by 18%. These results highlight the effectiveness of the proposed multi-objective dynamic shape control system in balancing production efficiency and product quality. The study provides theoretical insights and practical methodologies for intelligent process optimization in high-speed cold rolling applications.