Numerical and Experimental Analysis of Spring-back Defect in Flexible Roll Forming Process using Anisotropic Yield Criteria

The Flexible Roll Forming (FRF) process with the ability to produce parts with variable width and depth was formed to be used in industries such as automotive, construction, and similar industries. One of the disadvantages of this process is the spring-back defect, which prevents the desired profile from being achieved. In this paper, experimental and numerical analysis of the spring-back phenomenon using Hill, Barlat, and Von Mises yield criteria. Also, the effect of bending angle, material, and sheet thickness parameters on this defect was investigated. The process for the three types of 1050 aluminum, low carbon steel, and 430 stainless steel was simulated using the VUMAT subroutine of Abaqus software. In these simulations, for each material, three thicknesses of 0.4, 0.7 and 1 mm with bending angles of 25 and 45 degrees were considered. Experimental experiments were performed using the FRF machine. Validation of numerical simulation results was performed by comparing experimental results. The results showed that the Barlat criterion has a more accurate prediction of spring-back than the other two criteria. The results also showed that the spring-back ratio of sheets with a thickness of 0.4 mm compared to 1 mm for low carbon, aluminum, and stainless steel are 1.5, 2.5, and 3.2, respectively.