Development and validation of a numerical model for sheet metal roll forming

The latest trends in the automotive industry towards fuel efficient, lightweight and sustainable transport have increased the use of Ultra High Strength Steels in the body in white of the vehicles. However, the formability of these steels is poor at room temperature and new geometrical errors appear when they are formed using conventional forming processes. In this context, the conventional roll forming process is a very interesting process to form these new materials. Since the yield strength of these materials is higher, the risk of appearance of not desired longitudinal plastic strains decreases. On the other hand, using these materials higher spring back occurs in the profile and higher forces and amounts of energy are needed. The Finite Element simulation is a powerful tool to optimise the process and understand the complex behaviour of the strip during the roll forming processes. In the present work, a Finite Element model has been developed to model the roll forming process. Experimental tests have been performed using different Ultra High Strength Steels and the roll load, the roll torque, the longitudinal strain and the spring back of the profile have been measured experimentally. Finally, the validation of the finite element model has been made comparing numerical and experimental results.