In-process, real-time monitoring of forming forces in rotary draw bending process

Abstract Monitoring forming forces in metal forming processes is essential for analyzing process behaviors, mechanisms, and defect detection. This is particularly relevant in aluminum tube bending processes, where the dimensional quality of the formed product is sensitive to multiple upstream and in-process variables. This research presents a method for real-time, in-process monitoring of forming forces in rotary draw bending (RDB). By developing a set of innovative forming tools (clamp die, bend die, pressure die, etc.) with directional force sensors embedded, key forming forces are measured. Through a series of experiments, the measurement method was validated by analyzing both measured forces and calculated moments, demonstrating high measurement consistency. The systematic examination of measurement variations provided insights into the reliability and robustness of the method. Moreover, comparison with FE results supported the accuracy of the measurements. Additionally, laser-based measurements showed a good correlation between the measured springback angle and the calculated moment during bending. These findings lay the groundwork for the industrial implementation of in-process force measurements in RDB, advancing the production of tube components.