Formability Study in Roll Forming Process: Insights into the Influence of Process Parameters on Damage Distribution

In this study, the phenomenon of ductile fracture in single-stage roll forming processes was investigated. In this regard, the fracture behavior of the 6061-T6 aluminum alloy was examined using the Modified Mohr-Coulomb fracture criterion. Subsequently, the calibration of the fracture criterion was carried out using a combined experimental-simulation approach. The roll forming process was modeled using finite element analysis, and the fracture criterion was implemented within the appropriate subroutine of the finite element simulation. According to the results, the Modified Mohr-Coulomb criterion with a 4.47% error capability could predict the onset of fracture in the single-stage roll forming process. Considering the sensitivity of the damage distribution accuracy to the stress state during the process, the effects of process parameters including thickness, bending angle, and corner radius on the triaxial stress parameter were investigated. The results indicate that these parameters do not have a significant impact on the triaxial stress parameter, and its average value remains within the range of 0.057 throughout all cases. Therefore, the fracture prediction results obtained with this criterion can be extended to other roll forming scenarios. Based on this, the influence of process parameters on damage and fracture during the roll forming process was examined. According to the results, an increase in sheet thickness and bending angle leads to an increase in damage, while an increase in the corner radius results in a reduction in damage area and a delayed occurrence of fracture during the process