Investigation of the forming load in the chain-die forming process

Chain-die Forming is a novel sheet metal processing technology which can be considered as a combination of roll forming and stamping processes. The significantly enlarged virtual roll radius can reduce or even eliminate redundant deformation, prevent the material from excessive reverse loading cycles and reduce the longitudinal strain development during the forming process. Thus, the technology presents several advantages in manufacturing advanced high strength steel (AHSS) such as fewer forming stands required, shorter production line as well as less energy consumption. Since the knowledge of the forming force during the forming process is essential for process design, this paper aims to investigate the forming load numerically, analytically and experimentally. The results show that the finite element simulation models can provide accurate predictions regarding the total forming load as well as the longitudinal strain development. Meanwhile, an analytical approach is developed to estimate the characteristic forming load at crossbars and load-bearing pillars of the supporting mechanism to optimize the geometrical structure of the chain-die former based on numerical simulation results. By optimizing the supporting mechanism, the load distribution can be balanced, improving the reliability of the forming process. Furthermore, the approach can set the guidelines for the calibration of the production line, as well as provide additional information such as the position of the central line of the forming device. Therefore, the findings can benefit the process design of the chain-die forming technology, as well as improve the efficiency of the calibration procedure