Novel approach to computational simulation of cross roll straightening of bars

A new finite element formulation, aimed at the modeling of cross roll straightening of circular bars is presented. It is based on Eulerian description of elastoplastic material flow through a stationary finite element mesh, which is fixed in space and coupled with the multi-roller straightening machine. This approach leads to extremely effective computational algorithm which provides the relation between input parameters like curvature, diameter and material of the bar, straightening rollers geometry and intermeshing on one hand and output bar curvature and residual stress distribution on the other. Using this strategy, multiple repetition of the straightening process analysis for variable intermeshing scheme is a feasible task, aimed to optimization of roller intermeshing. Basic features of the algorithm are described, some verification results presented and compared with real experiments realized in industrial conditions. The industry was also a motivation for the optimization study, presented in the last part of paper. The results prove that the suggested solution strategy is a mighty tool for effective analysis of cross roll straightening and show a great potential for other types of straightening processes as well.