Numerical Study on Continuous-Bending-Under-Tension of 3rd Generation Steel

Sheet metal forming is one of the key processes in the manufacturing of parts for several industries, such as automotive, aerospace and packaging. However, it is often constrained by the onset of plastic instability, which limits uniform deformation. To address this challenge, considerable attention has been given to methods that enhance strength, formability, and energy absorption during forming processes. One such method is the continuous-bending-under-tension (CBT) deformation mechanism, which has shown potential in mitigating localized instability during plastic deformation. This study presents a numerical investigation of the CBT process using Abaqus 2017 to evaluate the forces generated in both the CBT equipment and material when processing high-strength materials. The reference material used is the USS CR980XG3™ AHSS, a third-generation, high-strength, high-elongation steel grade with retained austenite (980T/600Y). The study systematically analyzes the effects of key parameters, such as roll diameter, distance between rolls, depth setting, specimen thickness, and the number of deformation cycles, on the evolution of forces during the CBT process. The results demonstrate that both the forces applied by the rolls and those experienced by the specimen are significantly influenced by the distance between rolls, depth setting, and specimen thickness. In contrast, the roll diameters have minimal influence. These findings contribute to the optimization of the CBT process and provide valuable insights for future studies aimed at enhancing the performance and formability of various materials.