Flexible roll forming process of thin-walled round pipes with multi-specification

Aiming at the flexible forming of thin-walled round pipes with multiple specifications can’t be realized by the conventional roll forming (CRF) process without changing any rolls. A new flower pattern design and linear movement positioning of rolls method were proposed for the flexible roll forming (FRF) process. Three-dimensional finite element models of both the CRF process and the FRF process were established with the professional roll forming design software COPRA FEA RF 2019. A comparative investigation was conducted between the CRF process and the FRF process for manufacturing round pipes with various specifications. The results demonstrated that the axial force in the FRF process is reduced to 9.45% to 33.92% of that in the CRF process, the peak longitudinal strain exhibits an approximately linear relationship with the thickness to out diameter ratio of the round pipes, and minimal extension occurs at the strip edge during the FRF process, which provides effective theoretical guidance for subsequent industrial test verification.